diff --git a/lib/jekyll/drops/url_drop.rb b/lib/jekyll/drops/url_drop.rb
index 6edb7d64..98a03f4a 100644
--- a/lib/jekyll/drops/url_drop.rb
+++ b/lib/jekyll/drops/url_drop.rb
@@ -125,7 +125,7 @@ module Jekyll
       private
 
       def fallback_data
-        {}
+        @fallback_data ||= {}
       end
     end
   end