diff --git a/library/ajax/index_data.php b/library/ajax/index_data.php
index 47447c85..debd9fcd 100644
--- a/library/ajax/index_data.php
+++ b/library/ajax/index_data.php
@@ -126,6 +126,9 @@ switch($mode)
 			<td>'. $user_ratio .'</td>
 		';
 	break;
+
+    default:
+        $this->ajax_die('Invalid mode');
 }
 
 $this->response['html'] = $html;
diff --git a/library/ajax/manage_admin.php b/library/ajax/manage_admin.php
index 74311b2a..844e4722 100644
--- a/library/ajax/manage_admin.php
+++ b/library/ajax/manage_admin.php
@@ -110,6 +110,10 @@ switch ($mode)
 		$this->response['unlock_cron_html'] = '<span class="seed bold">'. $lang['ADMIN_UNLOCKED'] .'</span>';
 
 	break;
+
+    default:
+
+        $this->ajax_die('Invalid mode');
 }
 
 $this->response['mode'] = $mode;
\ No newline at end of file
diff --git a/library/ajax/manage_user.php b/library/ajax/manage_user.php
index b1783e08..c13263a4 100644
--- a/library/ajax/manage_user.php
+++ b/library/ajax/manage_user.php
@@ -78,6 +78,10 @@ switch ($mode)
 		$this->response['info'] = $lang['USER_ACTIVATE_OFF'];
 
 	break;
+
+    default:
+
+        $this->ajax_die('Invalid mode');
 }
 
 $this->response['mode'] = $mode;
diff --git a/library/ajax/mod_action.php b/library/ajax/mod_action.php
index 80153be0..fa7ea8be 100644
--- a/library/ajax/mod_action.php
+++ b/library/ajax/mod_action.php
@@ -127,4 +127,7 @@ switch ($mode)
 			</table><br />
 		';
 	break;
+
+    default:
+        $this->ajax_die('Invalid mode');
 }
\ No newline at end of file
diff --git a/library/ajax/sitemap.php b/library/ajax/sitemap.php
index 45decf5f..a29d81f1 100644
--- a/library/ajax/sitemap.php
+++ b/library/ajax/sitemap.php
@@ -49,6 +49,9 @@ switch ($mode)
 			$html .= '<br />'.$lang['SITEMAP_NOTIFY_SEARCH'].' Weblogs: <font style="color: red;">'.$lang['SITEMAP_ERROR'].'</font> URL: <a href="http://rpc.weblogs.com/pingSiteForm?name=InfraBlog&url='.urlencode($map_link).'" target="_blank">http://rpc.weblogs.com/pingSiteForm?name=InfraBlog&url='.$map_link.'</a>';
 		}
 	break;
+
+    default:
+        $this->ajax_die('Invalid mode');
 }
 
 $this->response['html'] = $html;
diff --git a/library/ajax/user_register.php b/library/ajax/user_register.php
index 818b95c2..3696ce95 100644
--- a/library/ajax/user_register.php
+++ b/library/ajax/user_register.php
@@ -66,6 +66,9 @@ switch($mode)
 			}
 		}
 	break;
+
+    default:
+        $this->ajax_die('Invalid mode');
 }
 
 $this->response['html'] = $html;