diff --git a/src/compiler/diagnosticMessages.json b/src/compiler/diagnosticMessages.json
index 785ac6f953b..6a14aab2aee 100644
--- a/src/compiler/diagnosticMessages.json
+++ b/src/compiler/diagnosticMessages.json
@@ -3451,6 +3451,10 @@
         "category": "Error",
         "code": 6189
     },
+    "Found 'package.json' at '{0}'. Package ID is '{1}'.": {
+        "category": "Message",
+        "code": 6190
+    },
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",
         "code": 7005
diff --git a/src/compiler/moduleNameResolver.ts b/src/compiler/moduleNameResolver.ts
index e8639ea3d5f..f72876bd5fc 100644
--- a/src/compiler/moduleNameResolver.ts
+++ b/src/compiler/moduleNameResolver.ts
@@ -960,13 +960,18 @@ namespace ts {
         const directoryExists = !onlyRecordFailures && directoryProbablyExists(nodeModuleDirectory, host);
         const packageJsonPath = pathToPackageJson(nodeModuleDirectory);
         if (directoryExists && host.fileExists(packageJsonPath)) {
-            if (traceEnabled) {
-                trace(host, Diagnostics.Found_package_json_at_0, packageJsonPath);
-            }
             const packageJsonContent = readJson(packageJsonPath, host);
             const packageId: PackageId = typeof packageJsonContent.name === "string" && typeof packageJsonContent.version === "string"
                 ? { name: packageJsonContent.name, subModuleName, version: packageJsonContent.version }
                 : undefined;
+            if (traceEnabled) {
+                if (packageId) {
+                    trace(host, Diagnostics.Found_package_json_at_0_Package_ID_is_1, packageJsonPath, packageIdToString(packageId));
+                }
+                else {
+                    trace(host, Diagnostics.Found_package_json_at_0, packageJsonPath);
+                }
+            }
             return { found: true, packageJsonContent, packageId };
         }
         else {
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 0d1bbf233a3..37fae7195ab 100755
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -1817,7 +1817,7 @@ namespace ts {
             }, shouldCreateNewSourceFile);
 
             if (packageId) {
-                const packageIdKey = `${packageId.name}/${packageId.subModuleName}@${packageId.version}`;
+                const packageIdKey = packageIdToString(packageId);
                 const fileFromPackageId = packageIdToSourceFile.get(packageIdKey);
                 if (fileFromPackageId) {
                     // Some other SourceFile already exists with this package name and version.
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 357e5179865..ffcdf42c67e 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -116,6 +116,11 @@ namespace ts {
         return a === b || a && b && a.name === b.name && a.subModuleName === b.subModuleName && a.version === b.version;
     }
 
+    export function packageIdToString({ name, subModuleName, version }: PackageId): string {
+        const fullName = subModuleName ? `${name}/${subModuleName}` : name;
+        return `${fullName}@${version}`;
+    }
+
     export function typeDirectiveIsEqualTo(oldResolution: ResolvedTypeReferenceDirective, newResolution: ResolvedTypeReferenceDirective): boolean {
         return oldResolution.resolvedFileName === newResolution.resolvedFileName && oldResolution.primary === newResolution.primary;
     }
diff --git a/tests/baselines/reference/duplicatePackage_relativeImportWithinPackage.trace.json b/tests/baselines/reference/duplicatePackage_relativeImportWithinPackage.trace.json
index 45f70fd8145..ae3917e931a 100644
--- a/tests/baselines/reference/duplicatePackage_relativeImportWithinPackage.trace.json
+++ b/tests/baselines/reference/duplicatePackage_relativeImportWithinPackage.trace.json
@@ -2,7 +2,7 @@
     "======== Resolving module 'foo/use' from '/index.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module 'foo/use' from 'node_modules' folder, target file type 'TypeScript'.",
-    "Found 'package.json' at '/node_modules/foo/package.json'.",
+    "Found 'package.json' at '/node_modules/foo/package.json'. Package ID is 'foo/use@1.2.3'.",
     "File '/node_modules/foo/use.ts' does not exist.",
     "File '/node_modules/foo/use.tsx' does not exist.",
     "File '/node_modules/foo/use.d.ts' exist - use it as a name resolution result.",
@@ -26,12 +26,12 @@
     "File '/node_modules/foo/index.ts' does not exist.",
     "File '/node_modules/foo/index.tsx' does not exist.",
     "File '/node_modules/foo/index.d.ts' exist - use it as a name resolution result.",
-    "Found 'package.json' at '/node_modules/foo/package.json'.",
+    "Found 'package.json' at '/node_modules/foo/package.json'. Package ID is 'foo@1.2.3'.",
     "======== Module name './index' was successfully resolved to '/node_modules/foo/index.d.ts'. ========",
     "======== Resolving module 'foo' from '/node_modules/a/index.d.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module 'foo' from 'node_modules' folder, target file type 'TypeScript'.",
-    "Found 'package.json' at '/node_modules/a/node_modules/foo/package.json'.",
+    "Found 'package.json' at '/node_modules/a/node_modules/foo/package.json'. Package ID is 'foo@1.2.3'.",
     "File '/node_modules/a/node_modules/foo.ts' does not exist.",
     "File '/node_modules/a/node_modules/foo.tsx' does not exist.",
     "File '/node_modules/a/node_modules/foo.d.ts' does not exist.",
diff --git a/tests/baselines/reference/duplicatePackage_relativeImportWithinPackage_scoped.trace.json b/tests/baselines/reference/duplicatePackage_relativeImportWithinPackage_scoped.trace.json
index cae4195aa3d..a753e3dfb9a 100644
--- a/tests/baselines/reference/duplicatePackage_relativeImportWithinPackage_scoped.trace.json
+++ b/tests/baselines/reference/duplicatePackage_relativeImportWithinPackage_scoped.trace.json
@@ -2,7 +2,7 @@
     "======== Resolving module '@foo/bar/use' from '/index.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module '@foo/bar/use' from 'node_modules' folder, target file type 'TypeScript'.",
-    "Found 'package.json' at '/node_modules/@foo/bar/package.json'.",
+    "Found 'package.json' at '/node_modules/@foo/bar/package.json'. Package ID is '@foo/bar/use@1.2.3'.",
     "File '/node_modules/@foo/bar/use.ts' does not exist.",
     "File '/node_modules/@foo/bar/use.tsx' does not exist.",
     "File '/node_modules/@foo/bar/use.d.ts' exist - use it as a name resolution result.",
@@ -26,12 +26,12 @@
     "File '/node_modules/@foo/bar/index.ts' does not exist.",
     "File '/node_modules/@foo/bar/index.tsx' does not exist.",
     "File '/node_modules/@foo/bar/index.d.ts' exist - use it as a name resolution result.",
-    "Found 'package.json' at '/node_modules/@foo/bar/package.json'.",
+    "Found 'package.json' at '/node_modules/@foo/bar/package.json'. Package ID is '@foo/bar@1.2.3'.",
     "======== Module name './index' was successfully resolved to '/node_modules/@foo/bar/index.d.ts'. ========",
     "======== Resolving module '@foo/bar' from '/node_modules/a/index.d.ts'. ========",
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module '@foo/bar' from 'node_modules' folder, target file type 'TypeScript'.",
-    "Found 'package.json' at '/node_modules/a/node_modules/@foo/bar/package.json'.",
+    "Found 'package.json' at '/node_modules/a/node_modules/@foo/bar/package.json'. Package ID is '@foo/bar@1.2.3'.",
     "File '/node_modules/a/node_modules/@foo/bar.ts' does not exist.",
     "File '/node_modules/a/node_modules/@foo/bar.tsx' does not exist.",
     "File '/node_modules/a/node_modules/@foo/bar.d.ts' does not exist.",
diff --git a/tests/baselines/reference/moduleResolution_packageJson_yesAtPackageRoot.trace.json b/tests/baselines/reference/moduleResolution_packageJson_yesAtPackageRoot.trace.json
index 3a87769891b..e852d58f2b3 100644
--- a/tests/baselines/reference/moduleResolution_packageJson_yesAtPackageRoot.trace.json
+++ b/tests/baselines/reference/moduleResolution_packageJson_yesAtPackageRoot.trace.json
@@ -3,7 +3,7 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module 'foo/bar' from 'node_modules' folder, target file type 'TypeScript'.",
     "File '/node_modules/foo/bar/package.json' does not exist.",
-    "Found 'package.json' at '/node_modules/foo/package.json'.",
+    "Found 'package.json' at '/node_modules/foo/package.json'. Package ID is 'foo/bar@1.2.3'.",
     "File '/node_modules/foo/bar.ts' does not exist.",
     "File '/node_modules/foo/bar.tsx' does not exist.",
     "File '/node_modules/foo/bar.d.ts' does not exist.",
@@ -13,7 +13,7 @@
     "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
     "Loading module 'foo/bar' from 'node_modules' folder, target file type 'JavaScript'.",
     "File '/node_modules/foo/bar/package.json' does not exist.",
-    "Found 'package.json' at '/node_modules/foo/package.json'.",
+    "Found 'package.json' at '/node_modules/foo/package.json'. Package ID is 'foo/bar@1.2.3'.",
     "File '/node_modules/foo/bar.js' does not exist.",
     "File '/node_modules/foo/bar.jsx' does not exist.",
     "File '/node_modules/foo/bar/index.js' exist - use it as a name resolution result.",
diff --git a/tests/baselines/reference/moduleResolution_packageJson_yesAtPackageRoot_fakeScopedPackage.trace.json b/tests/baselines/reference/moduleResolution_packageJson_yesAtPackageRoot_fakeScopedPackage.trace.json
index c28189a1f7d..19fe1f125bc 100644
--- a/tests/baselines/reference/moduleResolution_packageJson_yesAtPackageRoot_fakeScopedPackage.trace.json
+++ b/tests/baselines/reference/moduleResolution_packageJson_yesAtPackageRoot_fakeScopedPackage.trace.json
@@ -3,7 +3,7 @@
     "Module resolution kind is not specified, using 'NodeJs'.",
     "Loading module 'foo/@bar' from 'node_modules' folder, target file type 'TypeScript'.",
     "File '/node_modules/foo/@bar/package.json' does not exist.",
-    "Found 'package.json' at '/node_modules/foo/package.json'.",
+    "Found 'package.json' at '/node_modules/foo/package.json'. Package ID is 'foo/@bar@1.2.3'.",
     "File '/node_modules/foo/@bar.ts' does not exist.",
     "File '/node_modules/foo/@bar.tsx' does not exist.",
     "File '/node_modules/foo/@bar.d.ts' does not exist.",
@@ -13,7 +13,7 @@
     "Directory '/node_modules/@types' does not exist, skipping all lookups in it.",
     "Loading module 'foo/@bar' from 'node_modules' folder, target file type 'JavaScript'.",
     "File '/node_modules/foo/@bar/package.json' does not exist.",
-    "Found 'package.json' at '/node_modules/foo/package.json'.",
+    "Found 'package.json' at '/node_modules/foo/package.json'. Package ID is 'foo/@bar@1.2.3'.",
     "File '/node_modules/foo/@bar.js' does not exist.",
     "File '/node_modules/foo/@bar.jsx' does not exist.",
     "File '/node_modules/foo/@bar/index.js' exist - use it as a name resolution result.",