diff --git a/react-packager/src/Resolver/polyfills/require-unbundle.js b/react-packager/src/Resolver/polyfills/require-unbundle.js
index 87e85601..9c1e36e7 100644
--- a/react-packager/src/Resolver/polyfills/require-unbundle.js
+++ b/react-packager/src/Resolver/polyfills/require-unbundle.js
@@ -80,7 +80,7 @@ function unknownModuleError(id) {
   let message = 'Requiring unknown module "' + id + '".';
   if (__DEV__) {
     message +=
-      'If you are sure the module is there, try restarting the packager.';
+      'If you are sure the module is there, try restarting the packager or running "npm install".';
   }
   return Error(message);
 }
diff --git a/react-packager/src/Resolver/polyfills/require.js b/react-packager/src/Resolver/polyfills/require.js
index bc2824bb..764e4dd1 100644
--- a/react-packager/src/Resolver/polyfills/require.js
+++ b/react-packager/src/Resolver/polyfills/require.js
@@ -48,7 +48,7 @@ function requireImpl(id) {
   if (!mod) {
     var msg = 'Requiring unknown module "' + id + '"';
     if (__DEV__) {
-      msg += '. If you are sure the module is there, try restarting the packager.';
+      msg += '. If you are sure the module is there, try restarting the packager or running "npm install".';
     }
     throw new Error(msg);
   }