Index: /CKEditor/trunk/_source/core/lang.js
===================================================================
--- /CKEditor/trunk/_source/core/lang.js	(revision 4154)
+++ /CKEditor/trunk/_source/core/lang.js	(revision 4155)
@@ -95,5 +95,5 @@
 			// If no languageCode - fallback to browser or default.
 			// If languageCode - fallback to no-localized version or default.
-			if ( !languageCode || !CKEDITOR.lang[ languageCode ] )
+			if ( !languageCode || !CKEDITOR.lang.languages[ languageCode ] )
 				languageCode = this.detect( defaultLanguage, languageCode );