diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index ff2efa4a2cb..70c421f9d2b 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -658,7 +658,7 @@ namespace ts {
                 const start = new Date().getTime();
                 ensureDirectoriesExist(getDirectoryPath(normalizePath(fileName)));
 
-                if (options.watch && sys.createHash && sys.getModifiedTime) {
+                if (isWatchSet(options) && sys.createHash && sys.getModifiedTime) {
                     writeFileIfUpdated(fileName, data, writeByteOrderMark);
                 }
                 else {
diff --git a/src/compiler/tsc.ts b/src/compiler/tsc.ts
index b88dea9d96b..377aca78901 100644
--- a/src/compiler/tsc.ts
+++ b/src/compiler/tsc.ts
@@ -240,11 +240,6 @@ namespace ts {
         return typeof JSON === "object" && typeof JSON.parse === "function";
     }
 
-    function isWatchSet(options: CompilerOptions) {
-        // Firefox has Object.prototype.watch
-        return options.watch && options.hasOwnProperty("watch");
-    }
-
     export function executeCommandLine(args: string[]): void {
         const commandLine = parseCommandLine(args);
         let configFileName: string;                                 // Configuration file name (if any)
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index ee029b7249f..9d92fb064e4 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -2642,6 +2642,11 @@ namespace ts {
         }
         return carriageReturnLineFeed;
     }
+
+    export function isWatchSet(options: CompilerOptions) {
+        // Firefox has Object.prototype.watch
+        return options.watch && options.hasOwnProperty("watch");
+    }
 }
 
 namespace ts {