diff --git a/clientside_validation_jquery/js/cv.jquery.validate.js b/clientside_validation_jquery/js/cv.jquery.validate.js
index f4c43ce..1d508d7 100644
--- a/clientside_validation_jquery/js/cv.jquery.validate.js
+++ b/clientside_validation_jquery/js/cv.jquery.validate.js
@@ -5,7 +5,7 @@
 (function ($, Drupal, drupalSettings) {
 
   /**
-   * Attaches jQuery validate behavoir to forms.
+   * Attaches jQuery validate behavior to forms.
    *
    * @type {Drupal~behavior}
    *
@@ -25,6 +25,28 @@
       $(context).find('form').each(function() {
         $(this).validate(drupalSettings.cvJqueryValidateOptions);
       });
+      
+      // Update Drupal.Ajax.prototype.beforeSend only once.
+      if (typeof Drupal.Ajax !== 'undefined'
+        && typeof Drupal.Ajax.prototype.beforeSubmitCVOriginal === 'undefined') {
+          Drupal.Ajax.prototype.beforeSubmitCVOriginal = Drupal.Ajax.prototype.beforeSubmit;
+          Drupal.Ajax.prototype.beforeSubmit = function (form_values, element_settings, options) {
+            if (typeof this.$form !== 'undefined') {
+              $(this.$form).validate(drupalSettings.cvJqueryValidateOptions);
+              if (!this.$form.valid()) {
+                 this.ajaxing = false;
+                 this.$form.addClass('clientside-validation-ajax-submit-invalid');
+                 return false;
+              }
+              else {
+                this.$form.removeClass('clientside-validation-ajax-submit-invalid');
+              }
+            }
+
+            return this.beforeSubmitCVOriginal(form_values, element_settings, options);
+          };
+      }
     }
   };
+
 })(jQuery, Drupal, drupalSettings);