diff --git a/Makefile b/Makefile
index d59e4fa..e941b9b 100644
--- a/Makefile
+++ b/Makefile
@@ -30,6 +30,9 @@ rebuild-build:
 rebuild-switch:
 	$(TIME) time nixos-rebuild switch --fallback  --show-trace
 
+show-blackholed:
+	-ip route |grep blackhole |wc -l| awk '{print "Il y a "$$1" route(s) en blackhole"}' |cowsay
+
 show-diff-with-current:
 	-diff /run/current-system/configuration.nix /etc/nixos/configuration.nix