diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 872f5797b36..3befc988a18 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -942,7 +942,7 @@ namespace ts {
      *  [^./]                   # matches everything up to the first . character (excluding directory seperators)
      *  (\\.(?!min\\.js$))?     # matches . characters but not if they are part of the .min.js file extension
      */
-    const singleAsteriskRegexFragmentFiles = "([^./]|(\\.(?!min\\.js$))?)*";
+    const singleAsteriskRegexFragmentFiles = "([^./]|(\\.(?!min\\.js$))?)*";
     const singleAsteriskRegexFragmentOther = "[^/]*";
 
     export function getRegularExpressionForWildcard(specs: string[], basePath: string, usage: "files" | "directories" | "exclude") {
@@ -1196,6 +1196,14 @@ namespace ts {
         return options && options.allowJs ? allSupportedExtensions : supportedTypeScriptExtensions;
     }
 
+    export function hasJavaScriptFileExtension(fileName: string) {
+        return forEach(supportedJavascriptExtensions, extension => fileExtensionIs(fileName, extension));
+    }
+
+    export function hasTypeScriptFileExtension(fileName: string) {
+        return forEach(supportedTypeScriptExtensions, extension => fileExtensionIs(fileName, extension));
+    }
+
     export function isSupportedSourceFileName(fileName: string, compilerOptions?: CompilerOptions) {
         if (!fileName) { return false; }
 
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 4ae0005e9c5..c73cf37fdda 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -2718,14 +2718,6 @@ namespace ts {
         return symbol && symbol.valueDeclaration && (symbol.valueDeclaration.flags & NodeFlags.Default) ? symbol.valueDeclaration.localSymbol : undefined;
     }
 
-    export function hasJavaScriptFileExtension(fileName: string) {
-        return forEach(supportedJavascriptExtensions, extension => fileExtensionIs(fileName, extension));
-    }
-
-    export function hasTypeScriptFileExtension(fileName: string) {
-        return forEach(supportedTypeScriptExtensions, extension => fileExtensionIs(fileName, extension));
-    }
-
     /**
      * Replace each instance of non-ascii characters by one, two, three, or four escape sequences
      * representing the UTF-8 encoding of the character, and return the expanded char code list.
diff --git a/src/server/typingsInstaller/typingsInstaller.ts b/src/server/typingsInstaller/typingsInstaller.ts
index 7f2615b338e..aadb5241dde 100644
--- a/src/server/typingsInstaller/typingsInstaller.ts
+++ b/src/server/typingsInstaller/typingsInstaller.ts
@@ -1,5 +1,4 @@
 /// <reference path="../../services/JsTyping.ts"/>
-/// <reference path="../../services/shims.ts"/>
 /// <reference path="../types.d.ts"/>
 
 namespace ts.server.typingsInstaller {
diff --git a/src/services/jsTyping.ts b/src/services/jsTyping.ts
index 3b013a4a924..e87f361ca9b 100644
--- a/src/services/jsTyping.ts
+++ b/src/services/jsTyping.ts
@@ -1,7 +1,9 @@
 // Copyright (c) Microsoft. All rights reserved. Licensed under the Apache License, Version 2.0.
 // See LICENSE.txt in the project root for complete license information.
 
-/// <reference path='services.ts' />
+/// <reference path='../compiler/types.ts' />
+/// <reference path='../compiler/core.ts' />
+/// <reference path='../compiler/commandLineParser.ts' />
 
 /* @internal */
 namespace ts.JsTyping {
@@ -54,7 +56,10 @@ namespace ts.JsTyping {
         }
 
         // Only infer typings for .js and .jsx files
-        fileNames = filter(map(fileNames, normalizePath), f => scriptKindIs(f, /*LanguageServiceHost*/ undefined, ScriptKind.JS, ScriptKind.JSX));
+        fileNames = filter(map(fileNames, normalizePath), f => {
+            const kind = ensureScriptKind(f, getScriptKindFromFileName(f));
+            return kind === ScriptKind.JS || kind === ScriptKind.JSX;
+        });
 
         if (!safeList) {
             const result = readConfigFile(safeListPath, (path: string) => host.readFile(path));
@@ -170,7 +175,7 @@ namespace ts.JsTyping {
                 mergeTypings(filter(cleanedTypingNames, f => hasProperty(safeList, f)));
             }
 
-            const hasJsxFile = forEach(fileNames, f => scriptKindIs(f, /*LanguageServiceHost*/ undefined, ScriptKind.JSX));
+            const hasJsxFile = forEach(fileNames, f => ensureScriptKind(f, getScriptKindFromFileName(f)) === ScriptKind.JSX);
             if (hasJsxFile) {
                 mergeTypings(["react"]);
             }