diff --git a/ui/widgets/mouse.js b/ui/widgets/mouse.js
index ef9dd8dbe9..ce7ce8c749 100644
--- a/ui/widgets/mouse.js
+++ b/ui/widgets/mouse.js
@@ -90,9 +90,11 @@ return $.widget( "ui.mouse", {
 
 		var that = this,
 			btnIsLeft = event.which === 1,
-			elIsCancel = typeof this.options.cancel === "string" ?
-				$( event.target ).closest( this.options.cancel ).length :
-				false;
+			elIsCancel = typeof this.options.cancel === "function" ?
+				this.options.cancel.call( event.target, event ) :
+				( typeof this.options.cancel === "string" ?
+					$( event.target ).closest( this.options.cancel ).length :
+					false );
 		if ( !btnIsLeft || elIsCancel || !this._mouseCapture( event ) ) {
 			return true;
 		}