diff --git a/comex/src-mpi-mt/groups.c b/comex/src-mpi-mt/groups.c
index c8d43f7f8..01469f6f5 100644
--- a/comex/src-mpi-mt/groups.c
+++ b/comex/src-mpi-mt/groups.c
@@ -454,6 +454,7 @@ void comex_group_finalize()
         _igroup_free(previous_group_list_item);
     }
 
+    group_list = NULL;
     free(g_state.hostid);
     status = MPI_Comm_free(&(g_state.node_comm));
     COMEX_ASSERT(MPI_SUCCESS == status);
diff --git a/comex/src-mpi-pr/groups.c b/comex/src-mpi-pr/groups.c
index bd0064927..c6b2020f8 100644
--- a/comex/src-mpi-pr/groups.c
+++ b/comex/src-mpi-pr/groups.c
@@ -625,6 +625,7 @@ void comex_group_finalize()
         _igroup_free(previous_group_list_item);
     }
 
+    group_list = NULL;
     free(g_state.master);
     free(g_state.host);
     status = MPI_Comm_free(&(g_state.node_comm));
diff --git a/comex/src-mpi-pt/groups.c b/comex/src-mpi-pt/groups.c
index 2fa3f8979..3c0925528 100644
--- a/comex/src-mpi-pt/groups.c
+++ b/comex/src-mpi-pt/groups.c
@@ -489,6 +489,7 @@ void comex_group_finalize()
         _igroup_free(previous_group_list_item);
     }
 
+    group_list = NULL;
     free(g_state.master);
     free(g_state.hostid);
     status = MPI_Comm_free(&(g_state.node_comm));
diff --git a/comex/src-ofa/groups.c b/comex/src-ofa/groups.c
index d90eb1574..261ad14d8 100644
--- a/comex/src-ofa/groups.c
+++ b/comex/src-ofa/groups.c
@@ -335,4 +335,5 @@ void comex_group_finalize()
         comex_igroup_finalize(previous_group_list_item);
         free(previous_group_list_item);
     }
+    group_list = NULL;
 }