diff --git a/rails_panel/assets/javascripts/filters.js b/rails_panel/assets/javascripts/filters.js
index 9354d16..88dd5b1 100644
--- a/rails_panel/assets/javascripts/filters.js
+++ b/rails_panel/assets/javascripts/filters.js
@@ -48,4 +48,9 @@ angular.module('RailsPanel', [])
     return function(input) {
       return ansi2html(input);
     }
+  })
+  .filter('toString', function() {
+    return function(input) {
+      return input || "";
+    }
 });
diff --git a/rails_panel/panel.html b/rails_panel/panel.html
index d8a80c9..60253bc 100644
--- a/rails_panel/panel.html
+++ b/rails_panel/panel.html
@@ -232,7 +232,7 @@
                 <tbody>
                   <tr ng-repeat="log in activeLog()">
                     <td><a href="{{log.payload.filename | editorify:log.payload.line}}">{{log.payload.filename | normalizePath}}:{{log.payload.line}}</a></td>
-                    <td ng-bind-html-unsafe="log.payload.message | sanitize | ansi2html"></td>
+                    <td ng-bind-html-unsafe="log.payload.message | toString | sanitize | ansi2html"></td>
                   </tr>
                 </tbody>
               </table>