diff --git a/Jakefile.js b/Jakefile.js
index 7444f72a2dc..9156fe4109d 100644
--- a/Jakefile.js
+++ b/Jakefile.js
@@ -345,12 +345,17 @@ file(diagnosticInfoMapTs, [processDiagnosticMessagesJs, diagnosticMessagesJson],
         process.stderr.write(error);
     });
     ex.addListener("cmdEnd", function() {
-        jake.cpR(generatedDiagnosticMessagesJSON, builtGeneratedDiagnosticMessagesJSON)
         complete();
     });
     ex.run();
 }, {async: true});
 
+file(builtGeneratedDiagnosticMessagesJSON,[generatedDiagnosticMessagesJSON], function() {
+    if (fs.existsSync(builtLocalDirectory)) {
+        jake.cpR(generatedDiagnosticMessagesJSON, builtGeneratedDiagnosticMessagesJSON);
+    }
+}, {async: true});
+
 desc("Generates a diagnostic file in TypeScript based on an input JSON file");
 task("generate-diagnostics", [diagnosticInfoMapTs]);
 
@@ -479,7 +484,7 @@ task("lssl", [lsslFile]);
 
 // Local target to build the compiler and services
 desc("Builds the full compiler and services");
-task("local", ["generate-diagnostics", "lib", tscFile, servicesFile, nodeDefinitionsFile, serverFile]);
+task("local", ["generate-diagnostics", "lib", tscFile, servicesFile, nodeDefinitionsFile, serverFile, builtGeneratedDiagnosticMessagesJSON]);
 
 // Local target to build only tsc.js
 desc("Builds only the compiler");