diff --git a/cg_init_machine.sh b/cg_init_machine.sh
index 2b349d0..2feff57 100644
--- a/cg_init_machine.sh
+++ b/cg_init_machine.sh
@@ -1,7 +1,12 @@
 #!/bin/bash
 getent group wheel || groupadd wheel
 useradd cg_maintain_user
-groupmems -g wheel -a cg_maintain_user
+if command -v groupmems &> /dev/null
+then
+    groupmems -g wheel -a cg_maintain_user
+else
+    usermod -a -G wheel cg_maintain_user
+fi
 echo '%wheel ALL=(ALL:ALL) ALL' | EDITOR='tee -a' visudo
 mkdir -p /home/cg_maintain_user/.ssh
 touch /home/cg_maintain_user/.ssh/authorized_keys