diff --git a/src/compiler/moduleNameResolver.ts b/src/compiler/moduleNameResolver.ts
index 86e0157d847..f37b8ed1a19 100644
--- a/src/compiler/moduleNameResolver.ts
+++ b/src/compiler/moduleNameResolver.ts
@@ -14,6 +14,11 @@ namespace ts {
         return compilerOptions.traceResolution && host.trace !== undefined;
     }
 
+    /** Array that is only intended to be pushed to, never read. */
+    interface Push<T> {
+        push(value: T): void;
+    }
+
     /**
      * Result of trying to resolve a module.
      * At least one of `ts` and `js` should be defined, or the whole thing should be `undefined`.
@@ -62,8 +67,7 @@ namespace ts {
 
     interface ModuleResolutionState {
         host: ModuleResolutionHost;
-        // We only use this subset of the compiler options.
-        compilerOptions: { rootDirs?: string[], baseUrl?: string, paths?: MapLike<string[]> };
+        compilerOptions: CompilerOptions;
         traceEnabled: boolean;
     }
 
@@ -128,7 +132,9 @@ namespace ts {
             currentDirectory = host.getCurrentDirectory();
         }
 
-        return currentDirectory !== undefined && getDefaultTypeRoots(currentDirectory, host);
+        if (currentDirectory !== undefined) {
+            return getDefaultTypeRoots(currentDirectory, host);
+        }
     }
 
     /**
@@ -142,20 +148,12 @@ namespace ts {
         }
 
         let typeRoots: string[];
-
-        while (true) {
-            const atTypes = combinePaths(currentDirectory, nodeModulesAtTypes);
+        forEachAncestorDirectory(currentDirectory, directory => {
+            const atTypes = combinePaths(directory, nodeModulesAtTypes);
             if (host.directoryExists(atTypes)) {
                 (typeRoots || (typeRoots = [])).push(atTypes);
             }
-
-            const parent = getDirectoryPath(currentDirectory);
-            if (parent === currentDirectory) {
-                break;
-            }
-            currentDirectory = parent;
-        }
-
+        });
         return typeRoots;
     }
     const nodeModulesAtTypes = combinePaths("node_modules", "@types");
@@ -233,7 +231,7 @@ namespace ts {
             if (traceEnabled) {
                 trace(host, Diagnostics.Looking_up_in_node_modules_folder_initial_location_0, initialLocationForSecondaryLookup);
             }
-            resolvedFile = resolvedTypeScriptOnly(loadModuleFromNodeModules(Extensions.DtsOnly, typeReferenceDirectiveName, initialLocationForSecondaryLookup, failedLookupLocations, moduleResolutionState, /*checkOneLevel*/ false));
+            resolvedFile = resolvedTypeScriptOnly(loadModuleFromNodeModules(Extensions.DtsOnly, typeReferenceDirectiveName, initialLocationForSecondaryLookup, failedLookupLocations, moduleResolutionState));
             if (traceEnabled) {
                 if (resolvedFile) {
                     trace(host, Diagnostics.Type_reference_directive_0_was_successfully_resolved_to_1_primary_Colon_2, typeReferenceDirectiveName, resolvedFile, false);
@@ -341,7 +339,7 @@ namespace ts {
      * 'typings' entry or file 'index' with some supported extension
      * - Classic loader will only try to interpret '/a/b/c' as file.
      */
-    type ResolutionKindSpecificLoader = (extensions: Extensions, candidate: string, failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState) => Resolved | undefined;
+    type ResolutionKindSpecificLoader = (extensions: Extensions, candidate: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState) => Resolved | undefined;
 
     /**
      * Any module resolution kind can be augmented with optional settings: 'baseUrl', 'paths' and 'rootDirs' - they are used to
@@ -404,7 +402,7 @@ namespace ts {
      * entries in 'rootDirs', use them to build absolute path out of (*) and try to resolve module from this location.
      */
     function tryLoadModuleUsingOptionalResolutionSettings(extensions: Extensions, moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
-        failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
+        failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
 
         if (moduleHasNonRelativeName(moduleName)) {
             return tryLoadModuleUsingBaseUrl(extensions, moduleName, loader, failedLookupLocations, state);
@@ -415,7 +413,7 @@ namespace ts {
     }
 
     function tryLoadModuleUsingRootDirs(extensions: Extensions, moduleName: string, containingDirectory: string, loader: ResolutionKindSpecificLoader,
-        failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
+        failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
 
         if (!state.compilerOptions.rootDirs) {
             return undefined;
@@ -491,7 +489,7 @@ namespace ts {
         return undefined;
     }
 
-    function tryLoadModuleUsingBaseUrl(extensions: Extensions, moduleName: string, loader: ResolutionKindSpecificLoader, failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
+    function tryLoadModuleUsingBaseUrl(extensions: Extensions, moduleName: string, loader: ResolutionKindSpecificLoader, failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
         if (!state.compilerOptions.baseUrl) {
             return undefined;
         }
@@ -562,7 +560,7 @@ namespace ts {
                 if (traceEnabled) {
                     trace(host, Diagnostics.Loading_module_0_from_node_modules_folder, moduleName);
                 }
-                const resolved = loadModuleFromNodeModules(extensions, moduleName, containingDirectory, failedLookupLocations, state, /*checkOneLevel*/ false);
+                const resolved = loadModuleFromNodeModules(extensions, moduleName, containingDirectory, failedLookupLocations, state);
                 return resolved && { resolved, isExternalLibraryImport: true };
             }
             else {
@@ -585,7 +583,7 @@ namespace ts {
         return { path: real, extension: resolved.extension };
     }
 
-    function nodeLoadModuleByRelativeName(extensions: Extensions, candidate: string, failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
+    function nodeLoadModuleByRelativeName(extensions: Extensions, candidate: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
         if (state.traceEnabled) {
             trace(state.host, Diagnostics.Loading_module_as_file_Slash_folder_candidate_module_location_0, candidate);
         }
@@ -604,7 +602,7 @@ namespace ts {
      * @param {boolean} onlyRecordFailures - if true then function won't try to actually load files but instead record all attempts as failures. This flag is necessary
      * in cases when we know upfront that all load attempts will fail (because containing folder does not exists) however we still need to record all failed lookup locations.
      */
-    function loadModuleFromFile(extensions: Extensions, candidate: string, failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
+    function loadModuleFromFile(extensions: Extensions, candidate: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
         // First, try adding an extension. An import of "foo" could be matched by a file "foo.ts", or "foo.js" by "foo.js.ts"
         const resolvedByAddingExtension = tryAddingExtensions(candidate, extensions, failedLookupLocations, onlyRecordFailures, state);
         if (resolvedByAddingExtension) {
@@ -624,7 +622,7 @@ namespace ts {
     }
 
     /** Try to return an existing file that adds one of the `extensions` to `candidate`. */
-    function tryAddingExtensions(candidate: string, extensions: Extensions, failedLookupLocations: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
+    function tryAddingExtensions(candidate: string, extensions: Extensions, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
         if (!onlyRecordFailures) {
             // check if containing folder exists - if it doesn't then just record failures for all supported extensions without disk probing
             const directory = getDirectoryPath(candidate);
@@ -649,7 +647,7 @@ namespace ts {
     }
 
     /** Return the file if it exists. */
-    function tryFile(fileName: string, failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): string | undefined {
+    function tryFile(fileName: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): string | undefined {
         if (!onlyRecordFailures && state.host.fileExists(fileName)) {
             if (state.traceEnabled) {
                 trace(state.host, Diagnostics.File_0_exist_use_it_as_a_name_resolution_result, fileName);
@@ -660,12 +658,12 @@ namespace ts {
             if (state.traceEnabled) {
                 trace(state.host, Diagnostics.File_0_does_not_exist, fileName);
             }
-            failedLookupLocation.push(fileName);
+            failedLookupLocations.push(fileName);
             return undefined;
         }
     }
 
-    function loadNodeModuleFromDirectory(extensions: Extensions, candidate: string, failedLookupLocation: string[], onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
+    function loadNodeModuleFromDirectory(extensions: Extensions, candidate: string, failedLookupLocations: Push<string>, onlyRecordFailures: boolean, state: ModuleResolutionState): Resolved | undefined {
         const packageJsonPath = pathToPackageJson(candidate);
         const directoryExists = !onlyRecordFailures && directoryProbablyExists(candidate, state.host);
 
@@ -677,12 +675,12 @@ namespace ts {
             if (typesFile) {
                 const onlyRecordFailures = !directoryProbablyExists(getDirectoryPath(typesFile), state.host);
                 // A package.json "typings" may specify an exact filename, or may choose to omit an extension.
-                const fromFile = tryFile(typesFile, failedLookupLocation, onlyRecordFailures, state);
+                const fromFile = tryFile(typesFile, failedLookupLocations, onlyRecordFailures, state);
                 if (fromFile) {
                     // Note: this would allow a package.json to specify a ".js" file as typings. Maybe that should be forbidden.
                     return resolvedFromAnyFile(fromFile);
                 }
-                const x = tryAddingExtensions(typesFile, Extensions.TypeScript, failedLookupLocation, onlyRecordFailures, state);
+                const x = tryAddingExtensions(typesFile, Extensions.TypeScript, failedLookupLocations, onlyRecordFailures, state);
                 if (x) {
                     return x;
                 }
@@ -698,17 +696,17 @@ namespace ts {
                 trace(state.host, Diagnostics.File_0_does_not_exist, packageJsonPath);
             }
             // record package json as one of failed lookup locations - in the future if this file will appear it will invalidate resolution results
-            failedLookupLocation.push(packageJsonPath);
+            failedLookupLocations.push(packageJsonPath);
         }
 
-        return loadModuleFromFile(extensions, combinePaths(candidate, "index"), failedLookupLocation, !directoryExists, state);
+        return loadModuleFromFile(extensions, combinePaths(candidate, "index"), failedLookupLocations, !directoryExists, state);
     }
 
     function pathToPackageJson(directory: string): string {
         return combinePaths(directory, "package.json");
     }
 
-    function loadModuleFromNodeModulesFolder(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
+    function loadModuleFromNodeModulesFolder(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
         const nodeModulesFolder = combinePaths(directory, "node_modules");
         const nodeModulesFolderExists = directoryProbablyExists(nodeModulesFolder, state.host);
         const candidate = normalizePath(combinePaths(nodeModulesFolder, moduleName));
@@ -717,34 +715,30 @@ namespace ts {
             loadNodeModuleFromDirectory(extensions, candidate, failedLookupLocations, !nodeModulesFolderExists, state);
     }
 
-    function loadModuleFromNodeModules(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState, checkOneLevel: boolean): Resolved | undefined {
-        return loadModuleFromNodeModulesWorker(extensions, moduleName, directory, failedLookupLocations, state, checkOneLevel, /*typesOnly*/ false);
+    function loadModuleFromNodeModules(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
+        return loadModuleFromNodeModulesWorker(extensions, moduleName, directory, failedLookupLocations, state, /*typesOnly*/ false);
     }
-    function loadModuleFromNodeModulesAtTypes(moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
-        return loadModuleFromNodeModulesWorker(Extensions.TypeScript, moduleName, directory, failedLookupLocations, state, /*checkOneLevel*/ false, /*typesOnly*/ true);
+    function loadModuleFromNodeModulesAtTypes(moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState): Resolved | undefined {
+        // Extensions parameter here doesn't actually matter, because typesOnly ensures we're just doing @types lookup, which is always DtsOnly.
+        return loadModuleFromNodeModulesWorker(Extensions.DtsOnly, moduleName, directory, failedLookupLocations, state, /*typesOnly*/ true);
     }
 
-    function loadModuleFromNodeModulesWorker(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: string[], state: ModuleResolutionState, checkOneLevel: boolean, typesOnly: boolean): Resolved | undefined {
-        directory = normalizeSlashes(directory);
-        while (true) {
-            if (getBaseFileName(directory) !== "node_modules") {
-                const resolved = tryInDirectory();
-                if (resolved) {
-                    return resolved;
-                }
+    function loadModuleFromNodeModulesWorker(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState, typesOnly: boolean): Resolved | undefined {
+        return forEachAncestorDirectory(normalizeSlashes(directory), ancestorDirectory => {
+            if (getBaseFileName(ancestorDirectory) !== "node_modules") {
+                return loadModuleFromNodeModulesOneLevel(extensions, moduleName, ancestorDirectory, failedLookupLocations, state, typesOnly);
             }
+        });
+    }
 
-            const parentPath = getDirectoryPath(directory);
-            if (parentPath === directory || checkOneLevel) {
-                return undefined;
-            }
-
-            directory = parentPath;
+    /** Load a module from a single node_modules directory, but not from any ancestors' node_modules directories. */
+    function loadModuleFromNodeModulesOneLevel(extensions: Extensions, moduleName: string, directory: string, failedLookupLocations: Push<string>, state: ModuleResolutionState, typesOnly = false): Resolved | undefined {
+        const packageResult = typesOnly ? undefined : loadModuleFromNodeModulesFolder(extensions, moduleName, directory, failedLookupLocations, state);
+        if (packageResult) {
+            return packageResult;
         }
-
-        function tryInDirectory(): Resolved | undefined {
-            const packageResult = typesOnly ? undefined : loadModuleFromNodeModulesFolder(extensions, moduleName, directory, failedLookupLocations, state);
-            return packageResult || loadModuleFromNodeModulesFolder(extensions, combinePaths("@types", moduleName), directory, failedLookupLocations, state);
+        if (extensions !== Extensions.JavaScript) {
+            return loadModuleFromNodeModulesFolder(Extensions.DtsOnly, combinePaths("@types", moduleName), directory, failedLookupLocations, state);
         }
     }
 
@@ -764,7 +758,11 @@ namespace ts {
             }
 
             if (moduleHasNonRelativeName(moduleName)) {
-                const resolved = loadModuleFromAncestorDirectories(extensions, moduleName, containingDirectory, failedLookupLocations, state);
+                // Climb up parent directories looking for a module.
+                const resolved = forEachAncestorDirectory(containingDirectory, directory => {
+                    const searchName = normalizePath(combinePaths(directory, moduleName));
+                    return loadModuleFromFile(extensions, searchName, failedLookupLocations, /*onlyRecordFailures*/ false, state);
+                });
                 if (resolved) {
                     return resolved;
                 }
@@ -780,22 +778,6 @@ namespace ts {
         }
     }
 
-    /** Climb up parent directories looking for a module. */
-    function loadModuleFromAncestorDirectories(extensions: Extensions, moduleName: string, containingDirectory: string, failedLookupLocations: string[], state: ModuleResolutionState): Resolved | undefined {
-        while (true) {
-            const searchName = normalizePath(combinePaths(containingDirectory, moduleName));
-            const referencedSourceFile = loadModuleFromFile(extensions, searchName, failedLookupLocations, /*onlyRecordFailures*/ false, state);
-            if (referencedSourceFile) {
-                return referencedSourceFile;
-            }
-            const parentPath = getDirectoryPath(containingDirectory);
-            if (parentPath === containingDirectory) {
-                return undefined;
-            }
-            containingDirectory = parentPath;
-        }
-    }
-
     /**
      * LSHost may load a module from a global cache of typings.
      * This is the minumum code needed to expose that functionality; the rest is in LSHost.
@@ -808,8 +790,24 @@ namespace ts {
         }
         const state: ModuleResolutionState = { compilerOptions, host, traceEnabled };
         const failedLookupLocations: string[] = [];
-        const resolved = loadModuleFromNodeModules(Extensions.TypeScript, moduleName, globalCache, failedLookupLocations, state, /*checkOneLevel*/ true) ||
-            loadModuleFromNodeModules(Extensions.JavaScript, moduleName, globalCache, failedLookupLocations, state, /*checkOneLevel*/ true);
+        const resolved = loadModuleFromNodeModulesOneLevel(Extensions.DtsOnly, moduleName, globalCache, failedLookupLocations, state);
         return createResolvedModuleWithFailedLookupLocations(resolved, /*isExternalLibraryImport*/ true, failedLookupLocations);
     }
+
+    /** Calls `callback` on `directory` and every ancestor directory it has, returning the first defined result. */
+    function forEachAncestorDirectory<T>(directory: string, callback: (directory: string) => T | undefined): T | undefined {
+        while (true) {
+            const result = callback(directory);
+            if (result !== undefined) {
+                return result;
+            }
+
+            const parentPath = getDirectoryPath(directory);
+            if (parentPath === directory) {
+                return undefined;
+            }
+
+            directory = parentPath;
+        }
+    }
 }
\ No newline at end of file
diff --git a/src/harness/unittests/moduleResolution.ts b/src/harness/unittests/moduleResolution.ts
index 0e391445eba..35313e15308 100644
--- a/src/harness/unittests/moduleResolution.ts
+++ b/src/harness/unittests/moduleResolution.ts
@@ -197,13 +197,9 @@ namespace ts {
                     "/a/b/c/d/node_modules/foo/index.tsx",
                     "/a/b/c/d/node_modules/foo/index.d.ts",
 
-                    "/a/b/c/d/node_modules/@types/foo.ts",
-                    "/a/b/c/d/node_modules/@types/foo.tsx",
                     "/a/b/c/d/node_modules/@types/foo.d.ts",
                     "/a/b/c/d/node_modules/@types/foo/package.json",
 
-                    "/a/b/c/d/node_modules/@types/foo/index.ts",
-                    "/a/b/c/d/node_modules/@types/foo/index.tsx",
                     "/a/b/c/d/node_modules/@types/foo/index.d.ts",
 
                     "/a/b/c/node_modules/foo.ts",
@@ -215,13 +211,9 @@ namespace ts {
                     "/a/b/c/node_modules/foo/index.tsx",
                     "/a/b/c/node_modules/foo/index.d.ts",
 
-                    "/a/b/c/node_modules/@types/foo.ts",
-                    "/a/b/c/node_modules/@types/foo.tsx",
                     "/a/b/c/node_modules/@types/foo.d.ts",
                     "/a/b/c/node_modules/@types/foo/package.json",
 
-                    "/a/b/c/node_modules/@types/foo/index.ts",
-                    "/a/b/c/node_modules/@types/foo/index.tsx",
                     "/a/b/c/node_modules/@types/foo/index.d.ts",
                 ]);
             }
@@ -257,13 +249,9 @@ namespace ts {
                     "/a/node_modules/b/c/node_modules/d/node_modules/foo/index.tsx",
                     "/a/node_modules/b/c/node_modules/d/node_modules/foo/index.d.ts",
 
-                    "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo.ts",
-                    "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo.tsx",
                     "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo.d.ts",
                     "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo/package.json",
 
-                    "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo/index.ts",
-                    "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo/index.tsx",
                     "/a/node_modules/b/c/node_modules/d/node_modules/@types/foo/index.d.ts",
 
                     "/a/node_modules/b/c/node_modules/foo.ts",
@@ -275,13 +263,9 @@ namespace ts {
                     "/a/node_modules/b/c/node_modules/foo/index.tsx",
                     "/a/node_modules/b/c/node_modules/foo/index.d.ts",
 
-                    "/a/node_modules/b/c/node_modules/@types/foo.ts",
-                    "/a/node_modules/b/c/node_modules/@types/foo.tsx",
                     "/a/node_modules/b/c/node_modules/@types/foo.d.ts",
                     "/a/node_modules/b/c/node_modules/@types/foo/package.json",
 
-                    "/a/node_modules/b/c/node_modules/@types/foo/index.ts",
-                    "/a/node_modules/b/c/node_modules/@types/foo/index.tsx",
                     "/a/node_modules/b/c/node_modules/@types/foo/index.d.ts",
 
                     "/a/node_modules/b/node_modules/foo.ts",
@@ -293,13 +277,9 @@ namespace ts {
                     "/a/node_modules/b/node_modules/foo/index.tsx",
                     "/a/node_modules/b/node_modules/foo/index.d.ts",
 
-                    "/a/node_modules/b/node_modules/@types/foo.ts",
-                    "/a/node_modules/b/node_modules/@types/foo.tsx",
                     "/a/node_modules/b/node_modules/@types/foo.d.ts",
                     "/a/node_modules/b/node_modules/@types/foo/package.json",
 
-                    "/a/node_modules/b/node_modules/@types/foo/index.ts",
-                    "/a/node_modules/b/node_modules/@types/foo/index.tsx",
                     "/a/node_modules/b/node_modules/@types/foo/index.d.ts",
 
                     "/a/node_modules/foo.ts",
@@ -709,13 +689,9 @@ import b = require("./moduleB");
                     "/root/folder1/node_modules/file6/index.tsx",
                     "/root/folder1/node_modules/file6/index.d.ts",
 
-                    "/root/folder1/node_modules/@types/file6.ts",
-                    "/root/folder1/node_modules/@types/file6.tsx",
                     "/root/folder1/node_modules/@types/file6.d.ts",
 
                     "/root/folder1/node_modules/@types/file6/package.json",
-                    "/root/folder1/node_modules/@types/file6/index.ts",
-                    "/root/folder1/node_modules/@types/file6/index.tsx",
                     "/root/folder1/node_modules/@types/file6/index.d.ts",
                     // success on /root/node_modules/file6.ts
                 ], /*isExternalLibraryImport*/ true);
diff --git a/src/harness/unittests/reuseProgramStructure.ts b/src/harness/unittests/reuseProgramStructure.ts
index 386e02e2450..6dbd74e71d2 100644
--- a/src/harness/unittests/reuseProgramStructure.ts
+++ b/src/harness/unittests/reuseProgramStructure.ts
@@ -394,26 +394,14 @@ namespace ts {
                     "File '/fs.ts' does not exist.",
                     "File '/fs.tsx' does not exist.",
                     "File '/fs.d.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs.tsx' does not exist.",
                     "File '/a/b/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/a/b/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/a/b/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/a/b/node_modules/@types/fs/index.d.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs.tsx' does not exist.",
                     "File '/a/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/a/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/a/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/a/node_modules/@types/fs/index.d.ts' does not exist.",
-                    "File '/node_modules/@types/fs.ts' does not exist.",
-                    "File '/node_modules/@types/fs.tsx' does not exist.",
                     "File '/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/node_modules/@types/fs/index.d.ts' does not exist.",
                     "File '/a/b/fs.js' does not exist.",
                     "File '/a/b/fs.jsx' does not exist.",
@@ -448,26 +436,14 @@ namespace ts {
                     "File '/fs.ts' does not exist.",
                     "File '/fs.tsx' does not exist.",
                     "File '/fs.d.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs.tsx' does not exist.",
                     "File '/a/b/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/a/b/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/a/b/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/a/b/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/a/b/node_modules/@types/fs/index.d.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs.tsx' does not exist.",
                     "File '/a/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/a/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/a/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/a/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/a/node_modules/@types/fs/index.d.ts' does not exist.",
-                    "File '/node_modules/@types/fs.ts' does not exist.",
-                    "File '/node_modules/@types/fs.tsx' does not exist.",
                     "File '/node_modules/@types/fs.d.ts' does not exist.",
                     "File '/node_modules/@types/fs/package.json' does not exist.",
-                    "File '/node_modules/@types/fs/index.ts' does not exist.",
-                    "File '/node_modules/@types/fs/index.tsx' does not exist.",
                     "File '/node_modules/@types/fs/index.d.ts' does not exist.",
                     "File '/a/b/fs.js' does not exist.",
                     "File '/a/b/fs.jsx' does not exist.",
diff --git a/src/harness/unittests/tsserverProjectSystem.ts b/src/harness/unittests/tsserverProjectSystem.ts
index 7986137ca43..9c3c7a4cd5b 100644
--- a/src/harness/unittests/tsserverProjectSystem.ts
+++ b/src/harness/unittests/tsserverProjectSystem.ts
@@ -1662,12 +1662,8 @@ namespace ts.projectSystem {
                 "File '/a/b/node_modules/lib/index.ts' does not exist.",
                 "File '/a/b/node_modules/lib/index.tsx' does not exist.",
                 "File '/a/b/node_modules/lib/index.d.ts' does not exist.",
-                "File '/a/b/node_modules/@types/lib.ts' does not exist.",
-                "File '/a/b/node_modules/@types/lib.tsx' does not exist.",
                 "File '/a/b/node_modules/@types/lib.d.ts' does not exist.",
                 "File '/a/b/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/b/node_modules/@types/lib/index.ts' does not exist.",
-                "File '/a/b/node_modules/@types/lib/index.tsx' does not exist.",
                 "File '/a/b/node_modules/@types/lib/index.d.ts' does not exist.",
                 "File '/a/node_modules/lib.ts' does not exist.",
                 "File '/a/node_modules/lib.tsx' does not exist.",
@@ -1676,12 +1672,8 @@ namespace ts.projectSystem {
                 "File '/a/node_modules/lib/index.ts' does not exist.",
                 "File '/a/node_modules/lib/index.tsx' does not exist.",
                 "File '/a/node_modules/lib/index.d.ts' does not exist.",
-                "File '/a/node_modules/@types/lib.ts' does not exist.",
-                "File '/a/node_modules/@types/lib.tsx' does not exist.",
                 "File '/a/node_modules/@types/lib.d.ts' does not exist.",
                 "File '/a/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/node_modules/@types/lib/index.ts' does not exist.",
-                "File '/a/node_modules/@types/lib/index.tsx' does not exist.",
                 "File '/a/node_modules/@types/lib/index.d.ts' does not exist.",
                 "File '/node_modules/lib.ts' does not exist.",
                 "File '/node_modules/lib.tsx' does not exist.",
@@ -1690,12 +1682,8 @@ namespace ts.projectSystem {
                 "File '/node_modules/lib/index.ts' does not exist.",
                 "File '/node_modules/lib/index.tsx' does not exist.",
                 "File '/node_modules/lib/index.d.ts' does not exist.",
-                "File '/node_modules/@types/lib.ts' does not exist.",
-                "File '/node_modules/@types/lib.tsx' does not exist.",
                 "File '/node_modules/@types/lib.d.ts' does not exist.",
                 "File '/node_modules/@types/lib/package.json' does not exist.",
-                "File '/node_modules/@types/lib/index.ts' does not exist.",
-                "File '/node_modules/@types/lib/index.tsx' does not exist.",
                 "File '/node_modules/@types/lib/index.d.ts' does not exist.",
                 "Loading module 'lib' from 'node_modules' folder.",
                 "File '/a/b/node_modules/lib.js' does not exist.",
@@ -1703,46 +1691,23 @@ namespace ts.projectSystem {
                 "File '/a/b/node_modules/lib/package.json' does not exist.",
                 "File '/a/b/node_modules/lib/index.js' does not exist.",
                 "File '/a/b/node_modules/lib/index.jsx' does not exist.",
-                "File '/a/b/node_modules/@types/lib.js' does not exist.",
-                "File '/a/b/node_modules/@types/lib.jsx' does not exist.",
-                "File '/a/b/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/b/node_modules/@types/lib/index.js' does not exist.",
-                "File '/a/b/node_modules/@types/lib/index.jsx' does not exist.",
                 "File '/a/node_modules/lib.js' does not exist.",
                 "File '/a/node_modules/lib.jsx' does not exist.",
                 "File '/a/node_modules/lib/package.json' does not exist.",
                 "File '/a/node_modules/lib/index.js' does not exist.",
                 "File '/a/node_modules/lib/index.jsx' does not exist.",
-                "File '/a/node_modules/@types/lib.js' does not exist.",
-                "File '/a/node_modules/@types/lib.jsx' does not exist.",
-                "File '/a/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/node_modules/@types/lib/index.js' does not exist.",
-                "File '/a/node_modules/@types/lib/index.jsx' does not exist.",
                 "File '/node_modules/lib.js' does not exist.",
                 "File '/node_modules/lib.jsx' does not exist.",
                 "File '/node_modules/lib/package.json' does not exist.",
                 "File '/node_modules/lib/index.js' does not exist.",
                 "File '/node_modules/lib/index.jsx' does not exist.",
-                "File '/node_modules/@types/lib.js' does not exist.",
-                "File '/node_modules/@types/lib.jsx' does not exist.",
-                "File '/node_modules/@types/lib/package.json' does not exist.",
-                "File '/node_modules/@types/lib/index.js' does not exist.",
-                "File '/node_modules/@types/lib/index.jsx' does not exist.",
                 "======== Module name 'lib' was not resolved. ========",
                 `Auto discovery for typings is enabled in project '${proj.getProjectName()}'. Running extra resolution pass for module 'lib' using cache location '/a/cache'.`,
-                "File '/a/cache/node_modules/lib.ts' does not exist.",
-                "File '/a/cache/node_modules/lib.tsx' does not exist.",
                 "File '/a/cache/node_modules/lib.d.ts' does not exist.",
                 "File '/a/cache/node_modules/lib/package.json' does not exist.",
-                "File '/a/cache/node_modules/lib/index.ts' does not exist.",
-                "File '/a/cache/node_modules/lib/index.tsx' does not exist.",
                 "File '/a/cache/node_modules/lib/index.d.ts' does not exist.",
-                "File '/a/cache/node_modules/@types/lib.ts' does not exist.",
-                "File '/a/cache/node_modules/@types/lib.tsx' does not exist.",
                 "File '/a/cache/node_modules/@types/lib.d.ts' does not exist.",
                 "File '/a/cache/node_modules/@types/lib/package.json' does not exist.",
-                "File '/a/cache/node_modules/@types/lib/index.ts' does not exist.",
-                "File '/a/cache/node_modules/@types/lib/index.tsx' does not exist.",
                 "File '/a/cache/node_modules/@types/lib/index.d.ts' exist - use it as a name resolution result.",
             ]);
             checkProjectActualFiles(proj, [file1.path, lib.path]);
diff --git a/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json b/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json
index 3a9d8c4ea79..f6df1476088 100644
--- a/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json
+++ b/tests/baselines/reference/maxNodeModuleJsDepthDefaultsToZero.trace.json
@@ -9,12 +9,8 @@
     "File '/node_modules/shortid/index.ts' does not exist.",
     "File '/node_modules/shortid/index.tsx' does not exist.",
     "File '/node_modules/shortid/index.d.ts' does not exist.",
-    "File '/node_modules/@types/shortid.ts' does not exist.",
-    "File '/node_modules/@types/shortid.tsx' does not exist.",
     "File '/node_modules/@types/shortid.d.ts' does not exist.",
     "File '/node_modules/@types/shortid/package.json' does not exist.",
-    "File '/node_modules/@types/shortid/index.ts' does not exist.",
-    "File '/node_modules/@types/shortid/index.tsx' does not exist.",
     "File '/node_modules/@types/shortid/index.d.ts' does not exist.",
     "Loading module 'shortid' from 'node_modules' folder.",
     "File '/node_modules/shortid.js' does not exist.",
diff --git a/tests/baselines/reference/moduleResolutionWithExtensions_withAmbientPresent.trace.json b/tests/baselines/reference/moduleResolutionWithExtensions_withAmbientPresent.trace.json
index 9c6d96fc190..8d4217a92bd 100644
--- a/tests/baselines/reference/moduleResolutionWithExtensions_withAmbientPresent.trace.json
+++ b/tests/baselines/reference/moduleResolutionWithExtensions_withAmbientPresent.trace.json
@@ -9,12 +9,8 @@
     "File '/node_modules/js/index.ts' does not exist.",
     "File '/node_modules/js/index.tsx' does not exist.",
     "File '/node_modules/js/index.d.ts' does not exist.",
-    "File '/node_modules/@types/js.ts' does not exist.",
-    "File '/node_modules/@types/js.tsx' does not exist.",
     "File '/node_modules/@types/js.d.ts' does not exist.",
     "File '/node_modules/@types/js/package.json' does not exist.",
-    "File '/node_modules/@types/js/index.ts' does not exist.",
-    "File '/node_modules/@types/js/index.tsx' does not exist.",
     "File '/node_modules/@types/js/index.d.ts' does not exist.",
     "Loading module 'js' from 'node_modules' folder.",
     "File '/node_modules/js.js' does not exist.",
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
index ab7210d7d02..f468d864eef 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution3_node.trace.json
@@ -33,12 +33,8 @@
     "File 'c:/root/folder2/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/folder2/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/root/node_modules/file4.ts' does not exist.",
     "File 'c:/root/node_modules/file4.tsx' does not exist.",
@@ -47,12 +43,8 @@
     "File 'c:/root/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/node_modules/file4.ts' does not exist.",
     "File 'c:/node_modules/file4.tsx' does not exist.",
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
index ab7210d7d02..f468d864eef 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution4_node.trace.json
@@ -33,12 +33,8 @@
     "File 'c:/root/folder2/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/folder2/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/folder2/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/folder2/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/root/node_modules/file4.ts' does not exist.",
     "File 'c:/root/node_modules/file4.tsx' does not exist.",
@@ -47,12 +43,8 @@
     "File 'c:/root/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/node_modules/file4.ts' does not exist.",
     "File 'c:/node_modules/file4.tsx' does not exist.",
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
index 2efeefa24e5..92a98a1067c 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution5_node.trace.json
@@ -75,12 +75,8 @@
     "File 'c:/root/folder1/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/folder1/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/folder1/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/folder1/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/folder1/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/folder1/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/folder1/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/folder1/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/folder1/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/folder1/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/root/node_modules/file4.ts' does not exist.",
     "File 'c:/root/node_modules/file4.tsx' does not exist.",
@@ -89,12 +85,8 @@
     "File 'c:/root/node_modules/file4/index.ts' does not exist.",
     "File 'c:/root/node_modules/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/file4/index.d.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4.d.ts' does not exist.",
     "File 'c:/root/node_modules/@types/file4/package.json' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/file4/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/file4/index.d.ts' does not exist.",
     "File 'c:/node_modules/file4.ts' exist - use it as a name resolution result.",
     "Resolving real path for 'c:/node_modules/file4.ts', result 'c:/node_modules/file4.ts'",
diff --git a/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json b/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
index 48633c85e3b..cc33d8d1c37 100644
--- a/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
+++ b/tests/baselines/reference/pathMappingBasedModuleResolution7_node.trace.json
@@ -51,12 +51,8 @@
     "File 'c:/root/src/node_modules/module3/index.ts' does not exist.",
     "File 'c:/root/src/node_modules/module3/index.tsx' does not exist.",
     "File 'c:/root/src/node_modules/module3/index.d.ts' does not exist.",
-    "File 'c:/root/src/node_modules/@types/module3.ts' does not exist.",
-    "File 'c:/root/src/node_modules/@types/module3.tsx' does not exist.",
     "File 'c:/root/src/node_modules/@types/module3.d.ts' does not exist.",
     "File 'c:/root/src/node_modules/@types/module3/package.json' does not exist.",
-    "File 'c:/root/src/node_modules/@types/module3/index.ts' does not exist.",
-    "File 'c:/root/src/node_modules/@types/module3/index.tsx' does not exist.",
     "File 'c:/root/src/node_modules/@types/module3/index.d.ts' does not exist.",
     "File 'c:/root/node_modules/module3.ts' does not exist.",
     "File 'c:/root/node_modules/module3.tsx' does not exist.",
@@ -65,12 +61,8 @@
     "File 'c:/root/node_modules/module3/index.ts' does not exist.",
     "File 'c:/root/node_modules/module3/index.tsx' does not exist.",
     "File 'c:/root/node_modules/module3/index.d.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/module3.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/module3.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/module3.d.ts' does not exist.",
     "File 'c:/root/node_modules/@types/module3/package.json' does not exist.",
-    "File 'c:/root/node_modules/@types/module3/index.ts' does not exist.",
-    "File 'c:/root/node_modules/@types/module3/index.tsx' does not exist.",
     "File 'c:/root/node_modules/@types/module3/index.d.ts' does not exist.",
     "File 'c:/node_modules/module3.ts' does not exist.",
     "File 'c:/node_modules/module3.tsx' does not exist.",
diff --git a/tests/baselines/reference/typeRootsFromMultipleNodeModulesDirectories.trace.json b/tests/baselines/reference/typeRootsFromMultipleNodeModulesDirectories.trace.json
index eec78e40192..2befbbde729 100644
--- a/tests/baselines/reference/typeRootsFromMultipleNodeModulesDirectories.trace.json
+++ b/tests/baselines/reference/typeRootsFromMultipleNodeModulesDirectories.trace.json
@@ -9,12 +9,8 @@
     "File '/foo/bar/node_modules/xyz/index.ts' does not exist.",
     "File '/foo/bar/node_modules/xyz/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/foo/bar/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/xyz/index.d.ts' does not exist.",
     "File '/foo/node_modules/xyz.ts' does not exist.",
     "File '/foo/node_modules/xyz.tsx' does not exist.",
@@ -23,12 +19,8 @@
     "File '/foo/node_modules/xyz/index.ts' does not exist.",
     "File '/foo/node_modules/xyz/index.tsx' does not exist.",
     "File '/foo/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/foo/node_modules/@types/xyz.ts' does not exist.",
-    "File '/foo/node_modules/@types/xyz.tsx' does not exist.",
     "File '/foo/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/foo/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/foo/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/foo/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/foo/node_modules/@types/xyz/index.d.ts' does not exist.",
     "File '/node_modules/xyz.ts' does not exist.",
     "File '/node_modules/xyz.tsx' does not exist.",
@@ -37,12 +29,8 @@
     "File '/node_modules/xyz/index.ts' does not exist.",
     "File '/node_modules/xyz/index.tsx' does not exist.",
     "File '/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/node_modules/@types/xyz.ts' does not exist.",
-    "File '/node_modules/@types/xyz.tsx' does not exist.",
     "File '/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/node_modules/@types/xyz/index.d.ts' does not exist.",
     "Loading module 'xyz' from 'node_modules' folder.",
     "File '/foo/bar/node_modules/xyz.js' does not exist.",
@@ -50,31 +38,16 @@
     "File '/foo/bar/node_modules/xyz/package.json' does not exist.",
     "File '/foo/bar/node_modules/xyz/index.js' does not exist.",
     "File '/foo/bar/node_modules/xyz/index.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/xyz/index.jsx' does not exist.",
     "File '/foo/node_modules/xyz.js' does not exist.",
     "File '/foo/node_modules/xyz.jsx' does not exist.",
     "File '/foo/node_modules/xyz/package.json' does not exist.",
     "File '/foo/node_modules/xyz/index.js' does not exist.",
     "File '/foo/node_modules/xyz/index.jsx' does not exist.",
-    "File '/foo/node_modules/@types/xyz.js' does not exist.",
-    "File '/foo/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/foo/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/foo/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/foo/node_modules/@types/xyz/index.jsx' does not exist.",
     "File '/node_modules/xyz.js' does not exist.",
     "File '/node_modules/xyz.jsx' does not exist.",
     "File '/node_modules/xyz/package.json' does not exist.",
     "File '/node_modules/xyz/index.js' does not exist.",
     "File '/node_modules/xyz/index.jsx' does not exist.",
-    "File '/node_modules/@types/xyz.js' does not exist.",
-    "File '/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/node_modules/@types/xyz/index.jsx' does not exist.",
     "======== Module name 'xyz' was not resolved. ========",
     "======== Resolving module 'pdq' from '/foo/bar/a.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -86,12 +59,8 @@
     "File '/foo/bar/node_modules/pdq/index.ts' does not exist.",
     "File '/foo/bar/node_modules/pdq/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/pdq/index.d.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/pdq.d.ts' does not exist.",
     "File '/foo/bar/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/index.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/pdq/index.d.ts' does not exist.",
     "File '/foo/node_modules/pdq.ts' does not exist.",
     "File '/foo/node_modules/pdq.tsx' does not exist.",
@@ -100,12 +69,8 @@
     "File '/foo/node_modules/pdq/index.ts' does not exist.",
     "File '/foo/node_modules/pdq/index.tsx' does not exist.",
     "File '/foo/node_modules/pdq/index.d.ts' does not exist.",
-    "File '/foo/node_modules/@types/pdq.ts' does not exist.",
-    "File '/foo/node_modules/@types/pdq.tsx' does not exist.",
     "File '/foo/node_modules/@types/pdq.d.ts' does not exist.",
     "File '/foo/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/foo/node_modules/@types/pdq/index.ts' does not exist.",
-    "File '/foo/node_modules/@types/pdq/index.tsx' does not exist.",
     "File '/foo/node_modules/@types/pdq/index.d.ts' does not exist.",
     "File '/node_modules/pdq.ts' does not exist.",
     "File '/node_modules/pdq.tsx' does not exist.",
@@ -114,12 +79,8 @@
     "File '/node_modules/pdq/index.ts' does not exist.",
     "File '/node_modules/pdq/index.tsx' does not exist.",
     "File '/node_modules/pdq/index.d.ts' does not exist.",
-    "File '/node_modules/@types/pdq.ts' does not exist.",
-    "File '/node_modules/@types/pdq.tsx' does not exist.",
     "File '/node_modules/@types/pdq.d.ts' does not exist.",
     "File '/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/node_modules/@types/pdq/index.ts' does not exist.",
-    "File '/node_modules/@types/pdq/index.tsx' does not exist.",
     "File '/node_modules/@types/pdq/index.d.ts' does not exist.",
     "Loading module 'pdq' from 'node_modules' folder.",
     "File '/foo/bar/node_modules/pdq.js' does not exist.",
@@ -127,31 +88,16 @@
     "File '/foo/bar/node_modules/pdq/package.json' does not exist.",
     "File '/foo/bar/node_modules/pdq/index.js' does not exist.",
     "File '/foo/bar/node_modules/pdq/index.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/index.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/pdq/index.jsx' does not exist.",
     "File '/foo/node_modules/pdq.js' does not exist.",
     "File '/foo/node_modules/pdq.jsx' does not exist.",
     "File '/foo/node_modules/pdq/package.json' does not exist.",
     "File '/foo/node_modules/pdq/index.js' does not exist.",
     "File '/foo/node_modules/pdq/index.jsx' does not exist.",
-    "File '/foo/node_modules/@types/pdq.js' does not exist.",
-    "File '/foo/node_modules/@types/pdq.jsx' does not exist.",
-    "File '/foo/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/foo/node_modules/@types/pdq/index.js' does not exist.",
-    "File '/foo/node_modules/@types/pdq/index.jsx' does not exist.",
     "File '/node_modules/pdq.js' does not exist.",
     "File '/node_modules/pdq.jsx' does not exist.",
     "File '/node_modules/pdq/package.json' does not exist.",
     "File '/node_modules/pdq/index.js' does not exist.",
     "File '/node_modules/pdq/index.jsx' does not exist.",
-    "File '/node_modules/@types/pdq.js' does not exist.",
-    "File '/node_modules/@types/pdq.jsx' does not exist.",
-    "File '/node_modules/@types/pdq/package.json' does not exist.",
-    "File '/node_modules/@types/pdq/index.js' does not exist.",
-    "File '/node_modules/@types/pdq/index.jsx' does not exist.",
     "======== Module name 'pdq' was not resolved. ========",
     "======== Resolving module 'abc' from '/foo/bar/a.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
@@ -163,12 +109,8 @@
     "File '/foo/bar/node_modules/abc/index.ts' does not exist.",
     "File '/foo/bar/node_modules/abc/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/abc/index.d.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/abc.d.ts' does not exist.",
     "File '/foo/bar/node_modules/@types/abc/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/index.ts' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/index.tsx' does not exist.",
     "File '/foo/bar/node_modules/@types/abc/index.d.ts' does not exist.",
     "File '/foo/node_modules/abc.ts' does not exist.",
     "File '/foo/node_modules/abc.tsx' does not exist.",
@@ -177,12 +119,8 @@
     "File '/foo/node_modules/abc/index.ts' does not exist.",
     "File '/foo/node_modules/abc/index.tsx' does not exist.",
     "File '/foo/node_modules/abc/index.d.ts' does not exist.",
-    "File '/foo/node_modules/@types/abc.ts' does not exist.",
-    "File '/foo/node_modules/@types/abc.tsx' does not exist.",
     "File '/foo/node_modules/@types/abc.d.ts' does not exist.",
     "File '/foo/node_modules/@types/abc/package.json' does not exist.",
-    "File '/foo/node_modules/@types/abc/index.ts' does not exist.",
-    "File '/foo/node_modules/@types/abc/index.tsx' does not exist.",
     "File '/foo/node_modules/@types/abc/index.d.ts' does not exist.",
     "File '/node_modules/abc.ts' does not exist.",
     "File '/node_modules/abc.tsx' does not exist.",
@@ -191,12 +129,8 @@
     "File '/node_modules/abc/index.ts' does not exist.",
     "File '/node_modules/abc/index.tsx' does not exist.",
     "File '/node_modules/abc/index.d.ts' does not exist.",
-    "File '/node_modules/@types/abc.ts' does not exist.",
-    "File '/node_modules/@types/abc.tsx' does not exist.",
     "File '/node_modules/@types/abc.d.ts' does not exist.",
     "File '/node_modules/@types/abc/package.json' does not exist.",
-    "File '/node_modules/@types/abc/index.ts' does not exist.",
-    "File '/node_modules/@types/abc/index.tsx' does not exist.",
     "File '/node_modules/@types/abc/index.d.ts' does not exist.",
     "Loading module 'abc' from 'node_modules' folder.",
     "File '/foo/bar/node_modules/abc.js' does not exist.",
@@ -204,31 +138,16 @@
     "File '/foo/bar/node_modules/abc/package.json' does not exist.",
     "File '/foo/bar/node_modules/abc/index.js' does not exist.",
     "File '/foo/bar/node_modules/abc/index.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc.jsx' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/package.json' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/index.js' does not exist.",
-    "File '/foo/bar/node_modules/@types/abc/index.jsx' does not exist.",
     "File '/foo/node_modules/abc.js' does not exist.",
     "File '/foo/node_modules/abc.jsx' does not exist.",
     "File '/foo/node_modules/abc/package.json' does not exist.",
     "File '/foo/node_modules/abc/index.js' does not exist.",
     "File '/foo/node_modules/abc/index.jsx' does not exist.",
-    "File '/foo/node_modules/@types/abc.js' does not exist.",
-    "File '/foo/node_modules/@types/abc.jsx' does not exist.",
-    "File '/foo/node_modules/@types/abc/package.json' does not exist.",
-    "File '/foo/node_modules/@types/abc/index.js' does not exist.",
-    "File '/foo/node_modules/@types/abc/index.jsx' does not exist.",
     "File '/node_modules/abc.js' does not exist.",
     "File '/node_modules/abc.jsx' does not exist.",
     "File '/node_modules/abc/package.json' does not exist.",
     "File '/node_modules/abc/index.js' does not exist.",
     "File '/node_modules/abc/index.jsx' does not exist.",
-    "File '/node_modules/@types/abc.js' does not exist.",
-    "File '/node_modules/@types/abc.jsx' does not exist.",
-    "File '/node_modules/@types/abc/package.json' does not exist.",
-    "File '/node_modules/@types/abc/index.js' does not exist.",
-    "File '/node_modules/@types/abc/index.jsx' does not exist.",
     "======== Module name 'abc' was not resolved. ========",
     "======== Resolving type reference directive 'grumpy', containing file '/src/__inferred type names__.ts', root directory '/foo/node_modules/@types,/node_modules/@types'. ========",
     "Resolving with primary search path '/foo/node_modules/@types, /node_modules/@types'",
diff --git a/tests/baselines/reference/typeRootsFromNodeModulesInParentDirectory.trace.json b/tests/baselines/reference/typeRootsFromNodeModulesInParentDirectory.trace.json
index 4bb62bc255a..421c47d30ec 100644
--- a/tests/baselines/reference/typeRootsFromNodeModulesInParentDirectory.trace.json
+++ b/tests/baselines/reference/typeRootsFromNodeModulesInParentDirectory.trace.json
@@ -9,12 +9,8 @@
     "File '/src/node_modules/xyz/index.ts' does not exist.",
     "File '/src/node_modules/xyz/index.tsx' does not exist.",
     "File '/src/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/src/node_modules/@types/xyz.ts' does not exist.",
-    "File '/src/node_modules/@types/xyz.tsx' does not exist.",
     "File '/src/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/src/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/src/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/src/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/src/node_modules/@types/xyz/index.d.ts' does not exist.",
     "File '/node_modules/xyz.ts' does not exist.",
     "File '/node_modules/xyz.tsx' does not exist.",
@@ -23,12 +19,8 @@
     "File '/node_modules/xyz/index.ts' does not exist.",
     "File '/node_modules/xyz/index.tsx' does not exist.",
     "File '/node_modules/xyz/index.d.ts' does not exist.",
-    "File '/node_modules/@types/xyz.ts' does not exist.",
-    "File '/node_modules/@types/xyz.tsx' does not exist.",
     "File '/node_modules/@types/xyz.d.ts' does not exist.",
     "File '/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/node_modules/@types/xyz/index.ts' does not exist.",
-    "File '/node_modules/@types/xyz/index.tsx' does not exist.",
     "File '/node_modules/@types/xyz/index.d.ts' does not exist.",
     "Loading module 'xyz' from 'node_modules' folder.",
     "File '/src/node_modules/xyz.js' does not exist.",
@@ -36,21 +28,11 @@
     "File '/src/node_modules/xyz/package.json' does not exist.",
     "File '/src/node_modules/xyz/index.js' does not exist.",
     "File '/src/node_modules/xyz/index.jsx' does not exist.",
-    "File '/src/node_modules/@types/xyz.js' does not exist.",
-    "File '/src/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/src/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/src/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/src/node_modules/@types/xyz/index.jsx' does not exist.",
     "File '/node_modules/xyz.js' does not exist.",
     "File '/node_modules/xyz.jsx' does not exist.",
     "File '/node_modules/xyz/package.json' does not exist.",
     "File '/node_modules/xyz/index.js' does not exist.",
     "File '/node_modules/xyz/index.jsx' does not exist.",
-    "File '/node_modules/@types/xyz.js' does not exist.",
-    "File '/node_modules/@types/xyz.jsx' does not exist.",
-    "File '/node_modules/@types/xyz/package.json' does not exist.",
-    "File '/node_modules/@types/xyz/index.js' does not exist.",
-    "File '/node_modules/@types/xyz/index.jsx' does not exist.",
     "======== Module name 'xyz' was not resolved. ========",
     "======== Resolving type reference directive 'foo', containing file '/src/__inferred type names__.ts', root directory '/node_modules/@types'. ========",
     "Resolving with primary search path '/node_modules/@types'",
diff --git a/tests/baselines/reference/typingsLookup4.trace.json b/tests/baselines/reference/typingsLookup4.trace.json
index bb9d94f43b5..d1c29b1f11b 100644
--- a/tests/baselines/reference/typingsLookup4.trace.json
+++ b/tests/baselines/reference/typingsLookup4.trace.json
@@ -9,8 +9,6 @@
     "File '/node_modules/jquery/index.ts' does not exist.",
     "File '/node_modules/jquery/index.tsx' does not exist.",
     "File '/node_modules/jquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/jquery.ts' does not exist.",
-    "File '/node_modules/@types/jquery.tsx' does not exist.",
     "File '/node_modules/@types/jquery.d.ts' does not exist.",
     "Found 'package.json' at '/node_modules/@types/jquery/package.json'.",
     "'package.json' has 'typings' field 'jquery.d.ts' that references '/node_modules/@types/jquery/jquery.d.ts'.",
@@ -27,8 +25,6 @@
     "File '/node_modules/kquery/index.ts' does not exist.",
     "File '/node_modules/kquery/index.tsx' does not exist.",
     "File '/node_modules/kquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/kquery.ts' does not exist.",
-    "File '/node_modules/@types/kquery.tsx' does not exist.",
     "File '/node_modules/@types/kquery.d.ts' does not exist.",
     "Found 'package.json' at '/node_modules/@types/kquery/package.json'.",
     "'package.json' has 'typings' field 'kquery' that references '/node_modules/@types/kquery/kquery'.",
@@ -48,8 +44,6 @@
     "File '/node_modules/lquery/index.ts' does not exist.",
     "File '/node_modules/lquery/index.tsx' does not exist.",
     "File '/node_modules/lquery/index.d.ts' does not exist.",
-    "File '/node_modules/@types/lquery.ts' does not exist.",
-    "File '/node_modules/@types/lquery.tsx' does not exist.",
     "File '/node_modules/@types/lquery.d.ts' does not exist.",
     "Found 'package.json' at '/node_modules/@types/lquery/package.json'.",
     "'package.json' has 'typings' field 'lquery' that references '/node_modules/@types/lquery/lquery'.",
diff --git a/tests/baselines/reference/typingsLookupAmd.trace.json b/tests/baselines/reference/typingsLookupAmd.trace.json
index 496166926a8..843f16fe8c6 100644
--- a/tests/baselines/reference/typingsLookupAmd.trace.json
+++ b/tests/baselines/reference/typingsLookupAmd.trace.json
@@ -10,19 +10,11 @@
     "File '/b.ts' does not exist.",
     "File '/b.tsx' does not exist.",
     "File '/b.d.ts' does not exist.",
-    "File '/x/y/node_modules/@types/b.ts' does not exist.",
-    "File '/x/y/node_modules/@types/b.tsx' does not exist.",
     "File '/x/y/node_modules/@types/b.d.ts' does not exist.",
     "File '/x/y/node_modules/@types/b/package.json' does not exist.",
-    "File '/x/y/node_modules/@types/b/index.ts' does not exist.",
-    "File '/x/y/node_modules/@types/b/index.tsx' does not exist.",
     "File '/x/y/node_modules/@types/b/index.d.ts' does not exist.",
-    "File '/x/node_modules/@types/b.ts' does not exist.",
-    "File '/x/node_modules/@types/b.tsx' does not exist.",
     "File '/x/node_modules/@types/b.d.ts' does not exist.",
     "File '/x/node_modules/@types/b/package.json' does not exist.",
-    "File '/x/node_modules/@types/b/index.ts' does not exist.",
-    "File '/x/node_modules/@types/b/index.tsx' does not exist.",
     "File '/x/node_modules/@types/b/index.d.ts' exist - use it as a name resolution result.",
     "======== Module name 'b' was successfully resolved to '/x/node_modules/@types/b/index.d.ts'. ========",
     "======== Resolving module 'a' from '/x/node_modules/@types/b/index.d.ts'. ========",
@@ -42,33 +34,17 @@
     "File '/a.ts' does not exist.",
     "File '/a.tsx' does not exist.",
     "File '/a.d.ts' does not exist.",
-    "File '/x/node_modules/@types/b/node_modules/@types/a.ts' does not exist.",
-    "File '/x/node_modules/@types/b/node_modules/@types/a.tsx' does not exist.",
     "File '/x/node_modules/@types/b/node_modules/@types/a.d.ts' does not exist.",
     "File '/x/node_modules/@types/b/node_modules/@types/a/package.json' does not exist.",
-    "File '/x/node_modules/@types/b/node_modules/@types/a/index.ts' does not exist.",
-    "File '/x/node_modules/@types/b/node_modules/@types/a/index.tsx' does not exist.",
     "File '/x/node_modules/@types/b/node_modules/@types/a/index.d.ts' does not exist.",
-    "File '/x/node_modules/@types/node_modules/@types/a.ts' does not exist.",
-    "File '/x/node_modules/@types/node_modules/@types/a.tsx' does not exist.",
     "File '/x/node_modules/@types/node_modules/@types/a.d.ts' does not exist.",
     "File '/x/node_modules/@types/node_modules/@types/a/package.json' does not exist.",
-    "File '/x/node_modules/@types/node_modules/@types/a/index.ts' does not exist.",
-    "File '/x/node_modules/@types/node_modules/@types/a/index.tsx' does not exist.",
     "File '/x/node_modules/@types/node_modules/@types/a/index.d.ts' does not exist.",
-    "File '/x/node_modules/@types/a.ts' does not exist.",
-    "File '/x/node_modules/@types/a.tsx' does not exist.",
     "File '/x/node_modules/@types/a.d.ts' does not exist.",
     "File '/x/node_modules/@types/a/package.json' does not exist.",
-    "File '/x/node_modules/@types/a/index.ts' does not exist.",
-    "File '/x/node_modules/@types/a/index.tsx' does not exist.",
     "File '/x/node_modules/@types/a/index.d.ts' does not exist.",
-    "File '/node_modules/@types/a.ts' does not exist.",
-    "File '/node_modules/@types/a.tsx' does not exist.",
     "File '/node_modules/@types/a.d.ts' does not exist.",
     "File '/node_modules/@types/a/package.json' does not exist.",
-    "File '/node_modules/@types/a/index.ts' does not exist.",
-    "File '/node_modules/@types/a/index.tsx' does not exist.",
     "File '/node_modules/@types/a/index.d.ts' exist - use it as a name resolution result.",
     "======== Module name 'a' was successfully resolved to '/node_modules/@types/a/index.d.ts'. ========",
     "======== Resolving type reference directive 'a', containing file '/__inferred type names__.ts', root directory '/node_modules/@types'. ========",