diff --git a/Geo/GModelIO_MSH.cpp b/Geo/GModelIO_MSH.cpp
index 50608716c81bc9b3eb4356ac917ceebd5b27583d..a58b0aaed10663b5ae585f89c073ee3f1aa9169b 100644
--- a/Geo/GModelIO_MSH.cpp
+++ b/Geo/GModelIO_MSH.cpp
@@ -564,6 +564,8 @@ static void writeElementsMSH(FILE *fp, GModel *model, GEntity *ge, std::vector<T
   }
 }
 
+#warning periodic nodes are not correct in case the nodes are renumbered
+
 void writeMSHPeriodicNodes(FILE *fp, std::vector<GEntity*> &entities)
 {
   int count = 0;
@@ -589,7 +591,7 @@ void writeMSHPeriodicNodes(FILE *fp, std::vector<GEntity*> &entities)
            it != g_slave->correspondingVertices.end(); it++){
         MVertex *v1 = it->first;
         MVertex *v2 = it->second;
-        fprintf(fp, "%d %d\n", v1->getIndex(), v2->getIndex());
+        fprintf(fp, "%d %d\n", v1->getNum(), v2->getNum());
       }
     }
   }