diff --git a/dbaccess/source/ui/querydesign/JoinController.cxx b/dbaccess/source/ui/querydesign/JoinController.cxx
index ac483039587c..3852ef9d3322 100644
--- a/dbaccess/source/ui/querydesign/JoinController.cxx
+++ b/dbaccess/source/ui/querydesign/JoinController.cxx
@@ -170,7 +170,7 @@ OJoinDesignView* OJoinController::getJoinView()
 
 void OJoinController::disposing()
 {
-    m_pAddTableDialog   = NULL;
+    m_pAddTableDialog.disposeAndClear();
 
     OJoinController_BASE::disposing();