diff --git a/vtysh/vtysh_user.c b/vtysh/vtysh_user.c
index 248b181..584b61f 100644
--- a/vtysh/vtysh_user.c
+++ b/vtysh/vtysh_user.c
@@ -176,7 +176,11 @@
   struct vtysh_user *user;
   struct passwd *passwd;
 
-  passwd = getpwuid (geteuid ());
+  if ((passwd = getpwuid (geteuid ())) == NULL)
+  {
+    fprintf (stderr, "could not lookup user ID %d\n", (int) geteuid());
+    exit (1);
+  }
 
   user = user_lookup (passwd->pw_name);
   if (user && user->nopassword)