diff --git a/lib/ace/virtual_renderer.js b/lib/ace/virtual_renderer.js
index 88719079..18408b98 100644
--- a/lib/ace/virtual_renderer.js
+++ b/lib/ace/virtual_renderer.js
@@ -467,14 +467,14 @@ var VirtualRenderer = function(container, theme) {
             return;
 
         if (!gutterReady) {
-            var ch = this.$gutterLayer.element.children
-            var oldEl = ch[this.$gutterLineHighlight - this.layerConfig.firstRow];
-            if (oldEl)
-                dom.removeCssClass(oldEl, "ace_gutter_active_line");
+            var lineEl, ch = this.$gutterLayer.element.children;
+            var index = this.$gutterLineHighlight - this.layerConfig.firstRow;
+            if (index >= 0 && (lineEl = ch[index]))
+                dom.removeCssClass(lineEl, "ace_gutter_active_line");
 
-            var newEl = ch[i - this.layerConfig.firstRow];
-            if (newEl)
-                dom.addCssClass(newEl, "ace_gutter_active_line");
+            index = i - this.layerConfig.firstRow;
+            if (index >= 0 && (lineEl = ch[index]))
+                dom.addCssClass(lineEl, "ace_gutter_active_line");
         }
 
         this.$gutterLayer.removeGutterDecoration(this.$gutterLineHighlight, "ace_gutter_active_line");