diff --git a/notebook/static/notebook/js/codecell.js b/notebook/static/notebook/js/codecell.js
index 54781cf6f..20d217919 100644
--- a/notebook/static/notebook/js/codecell.js
+++ b/notebook/static/notebook/js/codecell.js
@@ -510,6 +510,7 @@ define([
     CodeCell.prototype.clear_output = function (wait) {
         this.output_area.clear_output(wait);
         this.set_input_prompt();
+        this.events.trigger('clearOutput.CodeCell', {cell: this});
     };