diff --git a/src/ajax.js b/src/ajax.js
index a6ee676d..caacb605 100644
--- a/src/ajax.js
+++ b/src/ajax.js
@@ -542,7 +542,7 @@ jQuery.extend({
 		};
 
 		// Remove hash character (#7531: and string promotion)
-		// Add protocol if not provided (#5856: IE7 issue with protocol-less urls)
+		// Add protocol if not provided (#5866: IE7 issue with protocol-less urls)
 		// We also use the url parameter if available
 		s.url = ( "" + ( url || s.url ) ).replace( rhash, "" ).replace( rprotocol, protocol + "//" );