diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 8a5e51dd110..69d019688b1 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -1725,7 +1725,7 @@ namespace ts {
         }
 
         function createTypeofType() {
-            return getUnionType(arrayFromMap(typeofEQFacts.keys(), s => getLiteralTypeForText(TypeFlags.StringLiteral, s)));
+            return getUnionType(convertToArray(typeofEQFacts.keys(), s => getLiteralTypeForText(TypeFlags.StringLiteral, s)));
         }
 
         // A reserved member name starts with two underscores, but the third character cannot be an underscore
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 486dd5b42c8..d11f9925c05 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -895,7 +895,7 @@ namespace ts {
         return result;
     }
 
-    export function arrayFromMap<T, U>(iterator: Iterator<T>, f: (value: T) => U) {
+    export function convertToArray<T, U>(iterator: Iterator<T>, f: (value: T) => U) {
         const result: U[] = [];
         for (let { value, done } = iterator.next(); !done; { value, done } = iterator.next()) {
             result.push(f(value));