diff --git a/ui/autocomplete.js b/ui/autocomplete.js
index 209fa71ae..a3db1a9f8 100644
--- a/ui/autocomplete.js
+++ b/ui/autocomplete.js
@@ -365,7 +365,7 @@ $.widget( "ui.autocomplete", {
 		}
 
 		if ( !element || !element[ 0 ] ) {
-			element = this.element.closest( ".ui-front" );
+			element = this.element.closest( ".ui-front, dialog" );
 		}
 
 		if ( !element.length ) {
diff --git a/ui/selectmenu.js b/ui/selectmenu.js
index 74e142d33..c52f6e452 100644
--- a/ui/selectmenu.js
+++ b/ui/selectmenu.js
@@ -586,7 +586,7 @@ return $.widget( "ui.selectmenu", {
 		}
 
 		if ( !element || !element[ 0 ] ) {
-			element = this.element.closest( ".ui-front" );
+			element = this.element.closest( ".ui-front, dialog" );
 		}
 
 		if ( !element.length ) {