diff --git a/src/scripts/intro.js b/src/scripts/intro.js
index 0b7ab04..2e96054 100644
--- a/src/scripts/intro.js
+++ b/src/scripts/intro.js
@@ -6,4 +6,4 @@
     } else {
         return factory(angular);
     }
-}(angular || null, function(angular) {
\ No newline at end of file
+}(typeof angular === 'undefined' ? null : angular, function(angular) {
\ No newline at end of file