diff --git a/moonlight/js/moonlight-skulk.js b/moonlight/js/moonlight-skulk.js
index caeb545..47d9b5a 100644
--- a/moonlight/js/moonlight-skulk.js
+++ b/moonlight/js/moonlight-skulk.js
@@ -1121,6 +1121,8 @@ GameState.prototype.update = function()
 
     function _draw_viewrect(x) {
 	var r = x.viewRectangle();
+	if ( r == null ) 
+	    continue;
 	this.shadowTexture.context.fillStyle = 'rgba(255, 255, 255)';
 	this.shadowTexture.context.fillRect(r.left, 
 					    r.top,