diff --git a/EgtGeomKernel.rc b/EgtGeomKernel.rc
index 688c161..1ac8091 100644
Binary files a/EgtGeomKernel.rc and b/EgtGeomKernel.rc differ
diff --git a/GdbIterator.cpp b/GdbIterator.cpp
index ae88e0a..9953a06 100644
--- a/GdbIterator.cpp
+++ b/GdbIterator.cpp
@@ -24,7 +24,9 @@ using namespace std ;
 IGdbIterator*
 CreateGdbIterator( IGeomDB* pGDB)
 {
-   return static_cast<IGdbIterator*> ( new GdbIterator( pGDB) ) ;
+   if ( dynamic_cast<GeomDB*>( pGDB) == nullptr)
+      return nullptr ;
+   return static_cast<IGdbIterator*> ( new GdbIterator( pGDB)) ;
 }
 
 //----------------------------------------------------------------------------