diff --git a/build.sh b/build.sh
index 6f04dc7eae9d44f34e649fb45137d0a06771fe57..6355ff25396fd9776fa648e917bea6fd7ffa05d6 100755
--- a/build.sh
+++ b/build.sh
@@ -1,5 +1,7 @@
 #!/bin/bash
 
+set -exu
+
 if [ -z ${SOURCE_DATE_EPOCH:+x} ] && git -C . rev-parse 2>/dev/null; then
 	export SOURCE_DATE_EPOCH=$(git log -1 --format=%ct)
 fi