diff --git a/lib/ace/css/editor.css b/lib/ace/css/editor.css
index 5057618f..5a748eba 100644
--- a/lib/ace/css/editor.css
+++ b/lib/ace/css/editor.css
@@ -267,11 +267,11 @@
     border: 1px solid transparent;
 }
 
-.ace_fold-widget.end {
+.ace_fold-widget.ace_end {
     background-image: url("data:image/png,%89PNG%0D%0A%1A%0A%00%00%00%0DIHDR%00%00%00%05%00%00%00%05%08%06%00%00%00%8Do%26%E5%00%00%004IDATx%DAm%C7%C1%09%000%08C%D1%8C%ECE%C8E(%8E%EC%02)%1EZJ%F1%C1'%04%07I%E1%E5%EE%CAL%F5%A2%99%99%22%E2%D6%1FU%B5%FE0%D9x%A7%26Wz5%0E%D5%00%00%00%00IEND%AEB%60%82");
 }
 
-.ace_fold-widget.closed {
+.ace_fold-widget.ace_closed {
     background-image: url("data:image/png,%89PNG%0D%0A%1A%0A%00%00%00%0DIHDR%00%00%00%03%00%00%00%06%08%06%00%00%00%06%E5%24%0C%00%00%009IDATx%DA5%CA%C1%09%000%08%03%C0%AC*(%3E%04%C1%0D%BA%B1%23%A4Uh%E0%20%81%C0%CC%F8%82%81%AA%A2%AArGfr%88%08%11%11%1C%DD%7D%E0%EE%5B%F6%F6%CB%B8%05Q%2F%E9tai%D9%00%00%00%00IEND%AEB%60%82");
 }
 
@@ -296,10 +296,10 @@
 .ace_dark .ace_fold-widget {
     background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAHklEQVQIW2P4//8/AzoGEQ7oGCaLLAhWiSwB146BAQCSTPYocqT0AAAAAElFTkSuQmCC");
 }
-.ace_dark .ace_fold-widget.end {
+.ace_dark .ace_fold-widget.ace_end {
     background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUAAAAFCAYAAACNbyblAAAAH0lEQVQIW2P4//8/AxQ7wNjIAjDMgC4AxjCVKBirIAAF0kz2rlhxpAAAAABJRU5ErkJggg==");
 }
-.ace_dark .ace_fold-widget.closed {
+.ace_dark .ace_fold-widget.ace_closed {
     background-image: url("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAMAAAAFCAYAAACAcVaiAAAAHElEQVQIW2P4//+/AxAzgDADlOOAznHAKgPWAwARji8UIDTfQQAAAABJRU5ErkJggg==");
 }
 .ace_dark .ace_fold-widget:hover {
@@ -314,7 +314,7 @@
     
     
     
-.ace_fold-widget.invalid {
+.ace_fold-widget.ace_invalid {
     background-color: #FFB4B4;
     border-color: #DE5555;
 }
diff --git a/lib/ace/layer/gutter.js b/lib/ace/layer/gutter.js
index be34f3c9..f04c317f 100644
--- a/lib/ace/layer/gutter.js
+++ b/lib/ace/layer/gutter.js
@@ -129,8 +129,8 @@ var Gutter = function(parentEl) {
                     c = foldWidgets[i] = this.session.getFoldWidget(i);
                 if (c)
                     html.push(
-                        "<span class='ace_fold-widget ", c,
-                        c == "start" && i == foldStart && i < fold.end.row ? " closed" : " open",
+                        "<span class='ace_fold-widget ace_", c,
+                        c == "start" && i == foldStart && i < fold.end.row ? " ace_closed" : " ace_open",
                         "' style='height:", config.lineHeight, "px",
                         "'></span>"
                     );
diff --git a/lib/ace/theme/ambiance.css b/lib/ace/theme/ambiance.css
index c7dfa72c..6db015ec 100644
--- a/lib/ace/theme/ambiance.css
+++ b/lib/ace/theme/ambiance.css
@@ -52,11 +52,11 @@
   color: #777;
 }
 
-.ace-ambiance .ace_gutter-layer .ace_gutter-cell .ace_fold-widget.open:after {
+.ace-ambiance .ace_gutter-layer .ace_gutter-cell .ace_fold-widget.ace_open:after {
   content: '▾'
 }
 
-.ace-ambiance .ace_gutter-layer .ace_gutter-cell .ace_fold-widget.closed:after {
+.ace-ambiance .ace_gutter-layer .ace_gutter-cell .ace_fold-widget.ace_closed:after {
   content: '‣'
 }