diff --git a/src/harness/harness.ts b/src/harness/harness.ts
index 6bbf1eae04c..55258162d23 100644
--- a/src/harness/harness.ts
+++ b/src/harness/harness.ts
@@ -1789,4 +1789,4 @@ namespace Harness {
     }
 
     if (Error) (<any>Error).stackTraceLimit = 1;
-}
\ No newline at end of file
+}
diff --git a/src/services/services.ts b/src/services/services.ts
index 50070d8fa73..cdf31ea3197 100644
--- a/src/services/services.ts
+++ b/src/services/services.ts
@@ -1951,17 +1951,11 @@ namespace ts {
 
     let commandLineOptionsStringToEnum: CommandLineOptionOfCustomType[];
 
-    /**
-     * Convert an option's string name of enum-value in compiler-options, "options", into its corresponding enum value if possible.
-     * This is necessary because JS users may pass in string values for enum compiler options (e.g. ModuleKind).
-     *
-     * @param options   a compiler-options used in transpilation which can contain string value to specify instead of enum values
-     * @param diagnostics   a list of Diagnostic which occur during conversion (e.g invalid option's value)
-     */
-    function ConvertStringForEnumNameInCompilerOptionsToEnumValue(options: CompilerOptions, diagnostics: Diagnostic[]): CompilerOptions {
+    /** JS users may pass in string values for enum compiler options (such as ModuleKind), so convert. */
+    function fixupCompilerOptions(options: CompilerOptions, diagnostics: Diagnostic[]): CompilerOptions {
         // Lazily create this value to fix module loading errors.
         commandLineOptionsStringToEnum = commandLineOptionsStringToEnum || <CommandLineOptionOfCustomType[]>filter(optionDeclarations, o =>
-            typeof o.type === "object" && !forEachValue(<Map<number | string>> o.type, v => typeof v !== "number"));
+            typeof o.type === "object" && !forEachValue(<Map<any>> o.type, v => typeof v !== "number"));
 
         options = clone(options);
 
@@ -1999,7 +1993,7 @@ namespace ts {
     export function transpileModule(input: string, transpileOptions: TranspileOptions): TranspileOutput {
         const diagnostics: Diagnostic[] = [];
 
-        const options: CompilerOptions = transpileOptions.compilerOptions ? ConvertStringForEnumNameInCompilerOptionsToEnumValue(transpileOptions.compilerOptions, diagnostics) : getDefaultCompilerOptions();
+        const options: CompilerOptions = transpileOptions.compilerOptions ? fixupCompilerOptions(transpileOptions.compilerOptions, diagnostics) : getDefaultCompilerOptions();
 
         options.isolatedModules = true;
 
diff --git a/tests/baselines/reference/disallowAsyncModifierInES5.js b/tests/baselines/reference/disallowAsyncModifierInES5.js
index e0997f13110..b26ce1084ee 100644
--- a/tests/baselines/reference/disallowAsyncModifierInES5.js
+++ b/tests/baselines/reference/disallowAsyncModifierInES5.js
@@ -1,7 +1,7 @@
 //// [disallowAsyncModifierInES5.ts]
-
-async function foo() { return 42; } // ERROR: Async functions are only available in ES6+
-let bar = async function () { return 42; } // OK, but should be an error
+
+async function foo() { return 42; } // ERROR: Async functions are only available in ES6+
+let bar = async function () { return 42; } // OK, but should be an error
 let baz = async () => 42; // OK, but should be an error
 
 //// [disallowAsyncModifierInES5.js]
@@ -20,4 +20,4 @@ function foo() {
 var bar = function () {
     return __awaiter(this, void 0, void 0, function* () { return 42; });
 }; // OK, but should be an error
-var baz = function () { return __awaiter(_this, void 0, void 0, function* () { return 42; }); }; // OK, but should be an error
+var baz = function () { return __awaiter(_this, void 0, void 0, function* () { return 42; }); }; // OK, but should be an error
\ No newline at end of file