1 files changed, 2 insertions, 1 deletions
diff --git a/src/Comm.c b/src/Comm.c
index fdcde7c..68e8fa7 100644
--- a/src/Comm.c
+++ b/src/Comm.c
@@ -510,7 +510,8 @@ int PUGH_DisableGArrayGroupComm(pGH *pughGH, int first_var, pComm *groupcomm)
 int PUGH_Barrier(const cGH *GH)
 {
 #ifdef CCTK_MPI
-  CACTUS_MPI_ERROR (MPI_Barrier (PUGH_pGH (GH)->PUGH_COMM_WORLD));
+  CACTUS_MPI_ERROR (MPI_Barrier (GH ? PUGH_pGH (GH)->PUGH_COMM_WORLD :
+                                      MPI_COMM_WORLD));
 #else
   GH = GH;
 #endif