diff --git a/include/simpleplugin/class_simplePlugin.inc b/include/simpleplugin/class_simplePlugin.inc
index d2fa4935d132aa5f94c74c6cb895dda753b37c2b..4503340a2dc2cc3c8ece2deb59f12af20b488e76 100644
--- a/include/simpleplugin/class_simplePlugin.inc
+++ b/include/simpleplugin/class_simplePlugin.inc
@@ -724,7 +724,7 @@ class simplePlugin extends plugin
   function check ()
   {
     @DEBUG (DEBUG_TRACE, __LINE__, __FUNCTION__, __FILE__, $this->dn, 'check');
-    $message = parent::check();
+    $message = array();
 
     foreach ($this->attributesInfo as $sectionInfo) {
       foreach ($sectionInfo['attrs'] as $attr) {
@@ -739,6 +739,20 @@ class simplePlugin extends plugin
       }
     }
 
+    $this->callHook('CHECK', array('nbCheckErrors' => count($message)), $returnOutput);
+    if (!empty($returnOutput)) {
+      $message[] = join("\n", $returnOutput);
+    }
+
+    /* Check entryCSN */
+    if (!empty($this->entryCSN)) {
+      $current_csn = getEntryCSN($this->dn);
+      if (($current_csn != $this->entryCSN) && !empty($current_csn)) {
+        $this->entryCSN = $current_csn;
+        $message[] = _('The object has changed since opened in FusionDirectory. All changes that may be done by others will get lost if you save this entry!');
+      }
+    }
+
     return $message;
   }