diff --git a/Core.js b/Core.js
index 2e87bc7..1f9d3f2 100644
--- a/Core.js
+++ b/Core.js
@@ -549,7 +549,7 @@ Core.prototype.findUsernamesFor = function(query) {
 /* Helper functions */
 
 function replaceURLWithHTMLLinks(text, entities, message_node) {
-    var exp = /(\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_()|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig;
+    var exp = /(([^\^]https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_()|!:,.;]*[-A-Z0-9+&@#\/%=~_|])/ig;
     return text.replace(exp, "<a href='$1'>$1</a>");
 
     /*