diff --git a/IPython/frontend/html/notebook/static/js/codecell.js b/IPython/frontend/html/notebook/static/js/codecell.js
index cbc2cfa..e61b50c 100644
--- a/IPython/frontend/html/notebook/static/js/codecell.js
+++ b/IPython/frontend/html/notebook/static/js/codecell.js
@@ -16,7 +16,9 @@ var IPython = (function (IPython) {
     var key   = IPython.utils.keycodes;
 
     var CodeCell = function (kernel) {
-        this.kernel = kernel;
+        // The kernel doesn't have to be set at creation time, in that case
+        // it will be null and set_kernel has to be called later.
+        this.kernel = kernel || null;
         this.code_mirror = null;
         this.input_prompt_number = null;
         this.tooltip_on_tab = true;
@@ -48,7 +50,7 @@ var IPython = (function (IPython) {
 
         // construct a completer only if class exist
         // otherwise no print view
-        if (IPython.Completer != undefined )
+        if (IPython.Completer !== undefined)
         {
             this.completer = new IPython.Completer(this);
         }
@@ -140,8 +142,14 @@ var IPython = (function (IPython) {
         return false;
     };
 
+
     // Kernel related calls.
 
+    CodeCell.prototype.set_kernel = function (kernel) {
+        this.kernel = kernel;
+    }
+
+
     CodeCell.prototype.execute = function () {
         this.output_area.clear_output(true, true, true);
         this.set_input_prompt('*');
diff --git a/IPython/frontend/html/notebook/static/js/notebook.js b/IPython/frontend/html/notebook/static/js/notebook.js
index 142a193..2a27ebc 100644
--- a/IPython/frontend/html/notebook/static/js/notebook.js
+++ b/IPython/frontend/html/notebook/static/js/notebook.js
@@ -888,6 +888,14 @@ var IPython = (function (IPython) {
         var base_url = $('body').data('baseKernelUrl') + "kernels";
         this.kernel = new IPython.Kernel(base_url);
         this.kernel.start(this.notebook_id);
+        // Now that the kernel has been created, tell the CodeCells about it.
+        var ncells = this.ncells();
+        for (var i=0; i<ncells; i++) {
+            var cell = this.get_cell(i);
+            if (cell instanceof IPython.CodeCell) {
+                cell.set_kernel(this.kernel)
+            };
+        };
     };
 
 
@@ -1076,10 +1084,6 @@ var IPython = (function (IPython) {
 
 
     Notebook.prototype.load_notebook_success = function (data, status, xhr) {
-        // Create the kernel before creating cells as they need to be passed it.
-        if (! this.read_only) {
-            this.start_kernel();
-        }
         this.fromJSON(data);
         if (this.ncells() === 0) {
             this.insert_cell_below('code');
@@ -1111,6 +1115,11 @@ var IPython = (function (IPython) {
                 width: 400
             });
         }
+        // Create the kernel after the notebook is completely loaded to prevent
+        // code execution upon loading, which is a security risk.
+        if (! this.read_only) {
+            this.start_kernel();
+        }
         $([IPython.events]).trigger('notebook_loaded.Notebook');
     };