diff --git a/live-build/ubuntu/hooks/020-canary-live.chroot_early b/live-build/ubuntu/hooks/020-canary-live.chroot_early
index 8a75ac78..64a3d7de 100755
--- a/live-build/ubuntu/hooks/020-canary-live.chroot_early
+++ b/live-build/ubuntu/hooks/020-canary-live.chroot_early
@@ -1,5 +1,7 @@
 #! /bin/sh
 
+set -eu
+
 case $PASS in
     minimal.standard.live)
         ;;