diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 3b2197d6efa..b65634565b7 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -506,7 +506,7 @@ namespace ts {
         return result;
     }
 
-    export function mapValues<T, U>(map: Map<T>, f: (key: string, value: T) => [string, U]): Map<U> {
+    export function mapEntries<T, U>(map: Map<T>, f: (key: string, value: T) => [string, U]): Map<U> {
         if (!map) {
             return undefined;
         }
diff --git a/src/harness/unittests/configurationExtension.ts b/src/harness/unittests/configurationExtension.ts
index 03eb825811b..c68d07f5123 100644
--- a/src/harness/unittests/configurationExtension.ts
+++ b/src/harness/unittests/configurationExtension.ts
@@ -89,7 +89,7 @@ namespace ts {
     });
 
     const caseInsensitiveBasePath = "c:/dev/";
-    const caseInsensitiveHost = new Utils.MockParseConfigHost(caseInsensitiveBasePath, /*useCaseSensitiveFileNames*/ false, mapValues(testContents, (key, content) => [`c:${key}`, content]));
+    const caseInsensitiveHost = new Utils.MockParseConfigHost(caseInsensitiveBasePath, /*useCaseSensitiveFileNames*/ false, mapEntries(testContents, (key, content) => [`c:${key}`, content]));
 
     const caseSensitiveBasePath = "/dev/";
     const caseSensitiveHost = new Utils.MockParseConfigHost(caseSensitiveBasePath, /*useCaseSensitiveFileNames*/ true, testContents);