diff --git a/lib/ace/test/mockrenderer.js b/lib/ace/test/mockrenderer.js
index be4cd520..412a418a 100644
--- a/lib/ace/test/mockrenderer.js
+++ b/lib/ace/test/mockrenderer.js
@@ -129,5 +129,8 @@ MockRenderer.prototype.showCursor = function() {
 MockRenderer.prototype.visualizeFocus = function() {
 };
 
+MockRenderer.prototype.setAnnotations = function() {
+};
+
 return MockRenderer;
 });