diff --git a/src/converse-register.js b/src/converse-register.js
index 73f79f729..5a7280cdb 100644
--- a/src/converse-register.js
+++ b/src/converse-register.js
@@ -433,11 +433,15 @@
                      *      (Event) ev - the submit event.
                      */
                     if (ev && ev.preventDefault) { ev.preventDefault(); }
-                    var $empty_inputs = this.$('input.required:emptyVal');
-                    if ($empty_inputs.length) {
-                        $empty_inputs.addClass('error');
-                        return;
-                    }
+                    var has_empty_inputs = _.reduce(document.querySelectorAll('input.required'),
+                        function (result, input) {
+                            if (input.value === '') {
+                                input.classList.add('error');
+                                return result + 1;
+                            }
+                            return result;
+                        }, 0);
+                    if (has_empty_inputs) { return; }
                     var $inputs = $(ev.target).find(':input:not([type=button]):not([type=submit])'),
                         iq = $iq({type: "set"}).c("query", {xmlns:Strophe.NS.REGISTER});
 
diff --git a/src/utils.js b/src/utils.js
index bbef45476..9dcd0b896 100755
--- a/src/utils.js
+++ b/src/utils.js
@@ -63,10 +63,6 @@
         return deferred.promise();
     };
 
-    $.expr[':'].emptyVal = function(obj){
-        return obj.value === '';
-    };
-
     $.fn.hasScrollBar = function() {
         if (!$.contains(document, this.get(0))) {
             return false;