diff --git a/core/misc/ajax.js b/core/misc/ajax.js
index f8a1cb0..d5fb9ba 100644
--- a/core/misc/ajax.js
+++ b/core/misc/ajax.js
@@ -714,7 +714,7 @@
     // attachBehaviors() called on the new content from processing the response
     // commands is not sufficient, because behaviors from the entire form need
     // to be reattached.
-    if (this.$form) {
+    if (this.$form && this.$form.parents('html').length > 0) {
       var settings = this.settings || drupalSettings;
       Drupal.attachBehaviors(this.$form.get(0), settings);
     }
@@ -776,7 +776,7 @@
     // Re-enable the element.
     $(this.element).prop('disabled', false);
     // Reattach behaviors, if they were detached in beforeSerialize().
-    if (this.$form) {
+    if (this.$form && this.$form.parents('html').length > 0) {
       var settings = response.settings || this.settings || drupalSettings;
       Drupal.attachBehaviors(this.$form.get(0), settings);
     }