diff --git a/options/auto-upgrade.nix b/options/auto-upgrade.nix
index d0f9829..0c84db4 100644
--- a/options/auto-upgrade.nix
+++ b/options/auto-upgrade.nix
@@ -165,7 +165,7 @@ in
                         activate_configuration="no"
 
                         # Check if any user sessions are open
-                        active_users=$(users | tr ' ' '\n' | sort | uniq | grep -vE '^(${concatStringsSep "|" cfg.rebootIgnoreUsersActive})$')
+                        active_users=$(users | tr ' ' '\n' | sort | uniq | grep -vE '^(${concatStringsSep "|" cfg.rebootIgnoreUsersActive})$' || true)
                         if [ "$reboot_allowed" = "yes" ] && [ -n "$active_users" ] ; then
                             reboot_allowed=no
                             email_body="$(printf "%s\n%s\n%s" "$email_body" "The system cannot reboot since the following users are active:" "$active_users")"