diff --git a/mollom.admin.inc b/mollom.admin.inc
index c1f984e..839df53 100644
--- a/mollom.admin.inc
+++ b/mollom.admin.inc
@@ -69,7 +69,19 @@ function mollom_admin_form_list() {
     }
     $row[] = l(t('Configure'), 'admin/settings/mollom/manage/' . $form_id);
     $row[] = l(t('Unprotect'), 'admin/settings/mollom/unprotect/' . $form_id);
-    $rows[] = $row;
+
+    $class = '';
+    if (isset($mollom_form['deleted'])) {
+      $class = 'error';
+      drupal_set_message(t('The %module module form %form_id no longer exists.', array(
+        '%form_id' => $form_id,
+        '%module' => $modules[$mollom_form['module']],
+      )), 'error');
+    }
+    $rows[] = array(
+      'class' => $class,
+      'data' => $row,
+    );
   }
 
   // Add a row to add a form.
diff --git a/mollom.module b/mollom.module
index 40723d9..948b20b 100644
--- a/mollom.module
+++ b/mollom.module
@@ -872,8 +872,9 @@ function mollom_form_list() {
  */
 function mollom_form_info($form_id, $module) {
   $form_info = module_invoke($module, 'mollom_form_info', $form_id);
+  // If no form info exists, then the form has vanished.
   if (empty($form_info)) {
-    $form_info = array();
+    return;
   }
 
   // Ensure default properties.
@@ -941,9 +942,12 @@ function mollom_form_load($form_id) {
 
       // Attach form registry information.
       $form_list = module_invoke($mollom_form['module'], 'mollom_form_list');
-      if (isset($form_list[$form_id])) {
-        $mollom_form += $form_list[$form_id];
+      if (!isset($form_list[$form_id])) {
+        $mollom_form['title'] = $form_id;
+        $mollom_form['deleted'] = TRUE;
+        return $mollom_form;
       }
+      $mollom_form += $form_list[$form_id];
       $mollom_form += mollom_form_info($form_id, $mollom_form['module']);
 
       cache_set($cid, $mollom_form);