diff --git a/common/content/util.js b/common/content/util.js
index 8ea3d22a..24a167e2 100644
--- a/common/content/util.js
+++ b/common/content/util.js
@@ -675,7 +675,7 @@ const util = { //{{{
 
             // Ok, not a valid proto. If it looks like URL-ish (foo.com/bar),
             // let Gecko figure it out.
-            if (/[.]/.test(url) && !/\s/.test(url) || /^[\w-.]+:\d+(?:\/|$)/.test(url))
+            if (/[.\/]/.test(url) && !/\s/.test(url) || /^[\w-.]+:\d+(?:\/|$)/.test(url))
                 return url;
 
             // TODO: it would be clearer if the appropriate call to