diff --git a/src/compiler/tsc.ts b/src/compiler/tsc.ts
index 5129f5e9efe..5420caabe7c 100644
--- a/src/compiler/tsc.ts
+++ b/src/compiler/tsc.ts
@@ -360,7 +360,7 @@ namespace ts {
             let newFileNames = ts.map(parsedCommandLine.fileNames, compilerHost.getCanonicalFileName);
             let canonicalRootFileNames = ts.map(rootFileNames, compilerHost.getCanonicalFileName);
 
-            if (!arrayIsEqualTo(newFileNames, canonicalRootFileNames, /*comparer*/ undefined, /*sortBeforeComparison*/ true)) {
+            if (!arrayIsEqualTo(newFileNames.sort(), canonicalRootFileNames.sort())) {
                 setCachedProgram(undefined);
                 startTimerForRecompilation();
             }
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index 37109d1aa73..2a16c2c71fb 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -82,7 +82,7 @@ namespace ts {
         return node.end - node.pos;
     }
 
-    export function arrayIsEqualTo<T>(arr1: T[], arr2: T[], comparer?: (a: T, b: T) => boolean, sortBeforeComparison = false): boolean {
+    export function arrayIsEqualTo<T>(arr1: T[], arr2: T[], comparer?: (a: T, b: T) => boolean): boolean {
         if (!arr1 || !arr2) {
             return arr1 === arr2;
         }
@@ -91,11 +91,6 @@ namespace ts {
             return false;
         }
 
-        if (sortBeforeComparison) {
-            arr1.sort();
-            arr2.sort();
-        }
-
         for (let i = 0; i < arr1.length; ++i) {
             let equals = comparer ? comparer(arr1[i], arr2[i]) : arr1[i] === arr2[i];
             if (!equals) {
diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index bd334279798..b98129f99e9 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -576,7 +576,7 @@ namespace ts.server {
             let newRootFiles = projectOptions.files.map((f => this.getCanonicalFileName(f)));
             let currentRootFiles = project.getRootFiles().map((f => this.getCanonicalFileName(f)));
 
-            if (!arrayIsEqualTo(currentRootFiles, newRootFiles, /*comparer*/ undefined, /*sortBeforeComparison*/ true)) {
+            if (!arrayIsEqualTo(currentRootFiles.sort(), newRootFiles.sort())) {
                 // For configured projects, the change is made outside the tsconfig file, and
                 // it is not likely to affect the project for other files opened by the client. We can 
                 // just update the current project.