diff --git a/src/STUBS/mpi.cpp b/src/STUBS/mpi.cpp
index 3f4cc5964f..13d0446e0b 100644
--- a/src/STUBS/mpi.cpp
+++ b/src/STUBS/mpi.cpp
@@ -424,6 +424,16 @@ int MPI_Group_incl(MPI_Group group, int n, int *ranks, MPI_Group *newgroup)
     *newgroup = group;
   return 0;
 }
+
+/* ---------------------------------------------------------------------- */
+
+int MPI_Group_free(MPI_Group *group)
+{
+  if (group)
+    *group = MPI_GROUP_NULL;
+  return 0;
+}
+
 /* ---------------------------------------------------------------------- */
 
 int MPI_Cart_create(MPI_Comm comm_old, int ndims, int *dims, int *periods, int reorder,
diff --git a/src/STUBS/mpi.h b/src/STUBS/mpi.h
index a39dadd484..1d0ab8413d 100644
--- a/src/STUBS/mpi.h
+++ b/src/STUBS/mpi.h
@@ -52,6 +52,7 @@
 #define MPI_UNDEFINED -1
 #define MPI_COMM_NULL -1
 #define MPI_GROUP_EMPTY -1
+#define MPI_GROUP_NULL -1
 
 #define MPI_ANY_SOURCE -1
 #define MPI_STATUS_IGNORE NULL
@@ -120,6 +121,7 @@ MPI_Comm MPI_Comm_f2c(MPI_Fint comm);
 int MPI_Comm_group(MPI_Comm comm, MPI_Group *group);
 int MPI_Comm_create(MPI_Comm comm, MPI_Group group, MPI_Comm *newcomm);
 int MPI_Group_incl(MPI_Group group, int n, int *ranks, MPI_Group *newgroup);
+int MPI_Group_free(MPI_Group *group);
 
 int MPI_Cart_create(MPI_Comm comm_old, int ndims, int *dims, int *periods, int reorder,
                     MPI_Comm *comm_cart);