diff --git a/Jakefile.js b/Jakefile.js
index 2e4a30c90c6..e55933ac03d 100644
--- a/Jakefile.js
+++ b/Jakefile.js
@@ -57,7 +57,7 @@ function measure(marker) {
 }
 
 var compilerSources = [
-    "dataStructures.ts",
+    "collections.ts",
     "core.ts",
     "performance.ts",
     "sys.ts",
@@ -92,7 +92,7 @@ var compilerSources = [
 });
 
 var servicesSources = [
-    "dataStructures.ts",
+    "collections.ts",
     "core.ts",
     "performance.ts",
     "sys.ts",
diff --git a/src/compiler/dataStructures.ts b/src/compiler/collections.ts
similarity index 95%
rename from src/compiler/dataStructures.ts
rename to src/compiler/collections.ts
index 57874c0f6c1..e553363e380 100644
--- a/src/compiler/dataStructures.ts
+++ b/src/compiler/collections.ts
@@ -8,7 +8,7 @@ namespace ts {
     const fullyFeaturedMaps = usingNativeMaps && "keys" in Map.prototype && "values" in Map.prototype && "entries" in Map.prototype;
 
     /** Extra Map methods that may not be available, so we must provide fallbacks. */
-    interface FullyFeaturedMap<K, V> extends Map<K, V> {
+    interface ES6Map<K, V> extends Map<K, V> {
         keys(): Iterator<K>;
         values(): Iterator<V>;
         entries(): Iterator<[K, V]>;
@@ -122,7 +122,7 @@ namespace ts {
 
     /** Iterates over entries in the map, returning the first output of `getResult` that is not `undefined`. */
     export const findInMap: <K, V, U>(map: Map<K, V>, getResult: (value: V, key: K) => U | undefined) => U | undefined = fullyFeaturedMaps
-        ? <K, V, U>(map: FullyFeaturedMap<K, V>, f: (value: V, key: K) => U | undefined) => {
+        ? <K, V, U>(map: ES6Map<K, V>, f: (value: V, key: K) => U | undefined) => {
             const iter = map.entries();
             while (true) {
                 const { value: pair, done } = iter.next();
@@ -147,7 +147,7 @@ namespace ts {
 
     /** Whether `predicate` is true for at least one entry in the map. */
     export const someInMap: <K, V>(map: Map<K, V>, predicate: (value: V, key: K) => boolean) => boolean = fullyFeaturedMaps
-        ? <K, V>(map: FullyFeaturedMap<K, V>, predicate: (value: V, key: K) => boolean) =>
+        ? <K, V>(map: ES6Map<K, V>, predicate: (value: V, key: K) => boolean) =>
             someInIterator(map.entries(), ([key, value]) => predicate(value, key))
         : <K, V>(map: Map<K, V>, predicate: (value: V, key: K) => boolean) => {
             let found = false;
@@ -159,13 +159,13 @@ namespace ts {
 
     /** Whether `predicate` is true for at least one key in the map. */
     export const someKeyInMap: <K>(map: Map<K, any>, predicate: (key: K) => boolean) => boolean = fullyFeaturedMaps
-        ? <K>(map: FullyFeaturedMap<K, any>, predicate: (key: K) => boolean) => someInIterator(map.keys(), predicate)
+        ? <K>(map: ES6Map<K, any>, predicate: (key: K) => boolean) => someInIterator(map.keys(), predicate)
         : <K>(map: Map<K, any>, predicate: (key: K) => boolean) =>
             someInMap(map, (_value, key) => predicate(key));
 
     /** Whether `predicate` is true for at least one value in the map. */
     export const someValueInMap: <T>(map: Map<any, T>, predicate: (value: T) => boolean) => boolean = fullyFeaturedMaps
-        ? <T>(map: FullyFeaturedMap<any, T>, predicate: (value: T) => boolean) =>
+        ? <T>(map: ES6Map<any, T>, predicate: (value: T) => boolean) =>
             someInIterator(map.values(), predicate)
         : someInMap;
 
@@ -186,7 +186,7 @@ namespace ts {
      * `for (const key of map.keys()) action(key);`
      */
     export const forEachKeyInMap: <K>(map: Map<K, any>, action: (key: K) => void) => void = fullyFeaturedMaps
-        ? <K>(map: FullyFeaturedMap<K, any>, f: (key: K) => void) => {
+        ? <K>(map: ES6Map<K, any>, f: (key: K) => void) => {
             const iter: Iterator<K> = map.keys();
             while (true) {
                 const { value: key, done } = iter.next();
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
index 65cbae6a7d2..8c06856d1b2 100644
--- a/src/compiler/core.ts
+++ b/src/compiler/core.ts
@@ -1,4 +1,4 @@
-/// <reference path="dataStructures.ts" />
+/// <reference path="collections.ts" />
 /// <reference path="types.ts"/>
 /// <reference path="performance.ts" />
 
@@ -916,7 +916,7 @@ namespace ts {
 
     /**
      * Returns the path except for its basename. Eg:
-     * 
+     *
      * /path/to/file.ext -> /path/to
      */
     export function getDirectoryPath(path: Path): Path;
diff --git a/src/compiler/tsconfig.json b/src/compiler/tsconfig.json
index 8dfa32b4884..19540367686 100644
--- a/src/compiler/tsconfig.json
+++ b/src/compiler/tsconfig.json
@@ -12,7 +12,7 @@
     },
     "files": [
         "core.ts",
-        "dataStructures.ts",
+        "collections.ts",
         "performance.ts",
         "sys.ts",
         "types.ts",
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index 419971a8654..69061d42d6d 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -13,7 +13,7 @@ namespace ts {
      * Map can only be instantiated using NumberMap and StringMap, which come with shims.
      *
      * Internet Explorer does not support iterator-returning methods, so those are not allowed here.
-     * But map-using functions in dataStructures.ts check for these features and use them where possible.
+     * But map-using functions in collections.ts check for these features and use them where possible.
      */
     export interface Map<K, V> {
         clear(): void;