diff --git a/moonlight/js/moonlight-skulk.js b/moonlight/js/moonlight-skulk.js
index 5b36c55..38bfa70 100644
--- a/moonlight/js/moonlight-skulk.js
+++ b/moonlight/js/moonlight-skulk.js
@@ -883,7 +883,8 @@ var AISprite = function(game, x, y, key, frame) {
     }
 
     this.update_new_values = function() {
-	this.timer.stop();
+	if ( this.timer !== null )
+	    this.timer.stop();
 	this.animations.destroy();
 	this.clearWordBubble();	
 	this.state = STATE_UNAWARE;