diff --git a/t/t1400-update-ref.sh b/t/t1400-update-ref.sh
index a2015d0977..208f56e518 100755
--- a/t/t1400-update-ref.sh
+++ b/t/t1400-update-ref.sh
@@ -730,6 +730,13 @@ test_expect_success 'stdin -z fails update with bad ref name' '
 	grep "fatal: invalid ref format: ~a" err
 '
 
+test_expect_success 'stdin -z treats empty new value as zeros' '
+	git update-ref $a $m &&
+	printf $F "update $a" "" "" >stdin &&
+	git update-ref -z --stdin <stdin &&
+	test_must_fail git rev-parse --verify -q $a
+'
+
 test_expect_success 'stdin -z fails update with no new value' '
 	printf $F "update $a" >stdin &&
 	test_must_fail git update-ref -z --stdin <stdin 2>err &&