diff --git a/nglib/nglib.cpp b/nglib/nglib.cpp
index 11a43ddb..f4439213 100644
--- a/nglib/nglib.cpp
+++ b/nglib/nglib.cpp
@@ -613,6 +613,7 @@ namespace nglib
          }
          */
          geo->AddEdges(readedges);
+	 readedges.SetSize(0);
       }
 
       if (geo->GetStatus() == STLTopology::STL_GOOD || geo->GetStatus() == STLTopology::STL_WARNING) return NG_OK;