diff --git a/lib/youtube_titles.rb b/lib/youtube_titles.rb
index d47f0d673..c17a8c948 100644
--- a/lib/youtube_titles.rb
+++ b/lib/youtube_titles.rb
@@ -18,5 +18,5 @@ module YoutubeTitles
       self[:youtube_titles][video_id] = youtube_title_for(video_id)
     end
   end
-  YOUTUBE_ID_REGEX = /youtube\.com.*?v=([A-Za-z0-9_\\\-]+)/
+  YOUTUBE_ID_REGEX = /youtube\.com.*?v=([A-Za-z0-9_\\\-]+)/ unless defined? YOUTUBE_ID_REGEX
 end