diff --git a/debi.sh b/debi.sh
index 930863d..d7319d5 100755
--- a/debi.sh
+++ b/debi.sh
@@ -163,6 +163,9 @@ while [ $# -gt 0 ]; do
                 11|bullseye)
                     suite=bullseye
                     daily_d_i=true
+                    ;;
+                *)
+                    err "Unsupported version: $2"
             esac
             shift
             ;;