diff --git a/brozzler/js-templates/simpledo.js.j2 b/brozzler/js-templates/simpledo.js.j2
index 8a0a819..17309e0 100644
--- a/brozzler/js-templates/simpledo.js.j2
+++ b/brozzler/js-templates/simpledo.js.j2
@@ -22,6 +22,13 @@ var umbraBehavior = {
 	IDLE_TIMEOUT_SEC : 10,
 	idleSince : null,
 
+	// https://github.com/jquery/jquery/blob/master/src/css/hiddenVisibleSelectors.js
+	// n.b. returns true for elements with visibility:hidden, which occupy
+	// screen real estate but are not visible, or clickable with the ui
+	isVisible : function(elem) {
+		return !!(elem.offsetWidth || elem.offsetHeight || elem.getClientRects().length);
+	},
+
 	intervalFunc : function() {
 		var didSomething = false;
 		var somethingLeftBelow = false;
@@ -43,6 +50,9 @@ var umbraBehavior = {
 			var doTargets = documents[j].querySelectorAll(cssSelector);
 
 			for ( var i = 0; i < doTargets.length; i++) {
+				if (!this.isVisible(doTargets[i])) {
+					continue;
+				}
 				if (doTargets[i].umbraDone && !doUntilTimeout) {
 					continue;
 				}