diff --git a/lib/marked.js b/lib/marked.js
index 09aa559a9a..47da4f52b6 100644
--- a/lib/marked.js
+++ b/lib/marked.js
@@ -620,7 +620,7 @@ inline.gfm = merge({}, inline.normal, {
     .getRegex()
 });
 
-inline.gfm.url = edit(inline.gfm.url)
+inline.gfm.url = edit(inline.gfm.url, 'i')
   .replace('email', inline.gfm._extended_email)
   .getRegex();
 /**
diff --git a/test/specs/marked/marked.json b/test/specs/marked/marked.json
index b64eda14cf..5f46f53640 100644
--- a/test/specs/marked/marked.json
+++ b/test/specs/marked/marked.json
@@ -83,6 +83,18 @@
     "html": "<p>``<em>test`</em></p>",
     "example": 14
   },
+  {
+    "section": "Autolinks",
+    "markdown": "HTTP://FOO.COM",
+    "html": "<p><a href=\"HTTP://FOO.COM\">HTTP://FOO.COM</a></p>",
+    "example": 17
+  },
+  {
+    "section": "Autolinks",
+    "markdown": "hTtP://fOo.CoM",
+    "html": "<p><a href=\"hTtP://fOo.CoM\">hTtP://fOo.CoM</a></p>",
+    "example": 18
+  },
   {
     "section": "Autolinks",
     "markdown": "~~hello@email.com~~",