diff --git a/React/Modules/RCTSourceCode.m b/React/Modules/RCTSourceCode.m
index f8d96fac6..1608aca70 100644
--- a/React/Modules/RCTSourceCode.m
+++ b/React/Modules/RCTSourceCode.m
@@ -31,8 +31,7 @@ RCT_EXPORT_METHOD(getScriptText:(RCTPromiseResolveBlock)resolve
 {
   if (RCT_DEV && self.scriptData && self.scriptURL) {
     NSString *scriptText = [[NSString alloc] initWithData:self.scriptData encoding:NSUTF8StringEncoding];
-
-    resolve(@{@"text": scriptText, @"url": self.scriptURL.absoluteString});
+    resolve(@{@"text": RCTNullIfNil(scriptText), @"url": self.scriptURL.absoluteString});
   } else {
     reject(RCTErrorUnavailable, nil, RCTErrorWithMessage(@"Source code is not available"));
   }
diff --git a/packager/react-packager/src/Resolver/polyfills/require-unbundle.js b/packager/react-packager/src/Resolver/polyfills/require-unbundle.js
index 70cd11391..fa774787e 100644
--- a/packager/react-packager/src/Resolver/polyfills/require-unbundle.js
+++ b/packager/react-packager/src/Resolver/polyfills/require-unbundle.js
@@ -9,15 +9,11 @@
 
 'use strict';
 
-const {ErrorUtils, nativeRequire} = global;
 global.require = require;
 global.__d = define;
 
 const modules = Object.create(null);
 
-const loadModule = ErrorUtils ?
-  guardedLoadModule : loadModuleImplementation;
-
 function define(moduleId, factory) {
   if (moduleId in modules) {
     // prevent repeated calls to `global.nativeRequire` to overwrite modules
@@ -36,20 +32,29 @@ function require(moduleId) {
   const module = modules[moduleId];
   return module && module.isInitialized
     ? module.exports
-    : loadModule(moduleId, module);
+    : guardedLoadModule(moduleId, module);
 }
 
+var inGuard = false;
 function guardedLoadModule(moduleId, module) {
-  try {
+  if (global.ErrorUtils && !inGuard) {
+    inGuard = true;
+    var returnValue;
+    try {
+      returnValue = loadModuleImplementation(moduleId, module);
+    } catch (e) {
+      global.ErrorUtils.reportFatalError(e);
+    }
+    inGuard = false;
+    return returnValue;
+  } else {
     return loadModuleImplementation(moduleId, module);
-  } catch (e) {
-    ErrorUtils.reportFatalError(e);
   }
 }
 
 function loadModuleImplementation(moduleId, module) {
   if (!module) {
-    nativeRequire(moduleId);
+    global.nativeRequire(moduleId);
     module = modules[moduleId];
   }
 
@@ -90,6 +95,7 @@ function loadModuleImplementation(moduleId, module) {
     module.isInitialized = false;
     module.hasError = true;
     module.exports = undefined;
+    throw e;
   }
 }