diff --git a/app/services/static.rb b/app/services/static.rb
index 8baf7ba84c9283d83050b6f7f8ef8849a07a3e3a..e4a97bec64ec141bb9cd8e279e4496fdc0c9d166 100644
--- a/app/services/static.rb
+++ b/app/services/static.rb
@@ -14,7 +14,7 @@ class Static
       }
     )
     # We don't want ' in the frontmatters!
-    string = string.gsub '&#39\;', "'"
+    string.gsub! '&#39\;', "'"
     string
   end
 end