diff --git a/mkosi.postinst b/mkosi.postinst
index ff92053..b5f3022 100755
--- a/mkosi.postinst
+++ b/mkosi.postinst
@@ -1,4 +1,6 @@
 #!/usr/bin/bash
+set -euo pipefail
+
 source /etc/os-release
 export OS=$ID