diff --git a/src/event.js b/src/event.js
index 38ed3ae91..fec3e6d49 100644
--- a/src/event.js
+++ b/src/event.js
@@ -492,6 +492,11 @@ jQuery.event = {
 		event = jQuery.Event( originalEvent );
 		propHook = jQuery.event.propHooks[ event.type ];
 
+		// Determine if an early return is possible
+		if ( !propHook && ( event.target && event.target.nodeType !== 3 ) && event.relatedTarget ) {
+			return event;
+		}
+
 		for ( var i = this.props.length, prop; i; ) {
 			prop = this.props[ --i ];
 			event[ prop ] = originalEvent[ prop ];