diff --git a/ajax_register.module b/ajax_register.module
index cb5e3e6..c40b311 100644
--- a/ajax_register.module
+++ b/ajax_register.module
@@ -212,8 +212,20 @@ function _ajax_register_add_ajax(&$form, $type) {
 
   // Add ajax wrapper to form.
   $html_id = str_replace('_', '-', $type);
-  $form['#prefix'] = '<div id="ajax-register-' . $html_id . '-wrapper">';
-  $form['#suffix'] = '</div>';
+
+  if(isset($form['#prefix']) && !empty($form['#prefix'])) {
+    $form['#prefix'] .= '<div id="ajax-register-' . $html_id . '-wrapper">';
+  }
+  else {
+    $form['#prefix'] = '<div id="ajax-register-' . $html_id . '-wrapper">';
+  }
+
+  if(isset($form['#suffix']) && !empty($form['#suffix'])) {
+    $form['#suffix'] = '</div>' . $form['#suffix'];
+  }
+  else {
+    $form['#suffix'] = '</div>';
+  }
 
   // User login block and user login form have same ajax callback;
   if ($type == 'user_login_block') {