diff --git a/IPython/html/static/services/kernels/js/kernel.js b/IPython/html/static/services/kernels/js/kernel.js
index 4654518..9d5806c 100644
--- a/IPython/html/static/services/kernels/js/kernel.js
+++ b/IPython/html/static/services/kernels/js/kernel.js
@@ -339,6 +339,7 @@ var IPython = (function (IPython) {
         var content = {
             text : '',
             line : line,
+            block : null,
             cursor_pos : cursor_pos
         };
         var msg = this._get_msg("complete_request", content);