diff --git a/t/t4012-diff-binary.sh b/t/t4012-diff-binary.sh
index 7b0e759c74..077870e95d 100755
--- a/t/t4012-diff-binary.sh
+++ b/t/t4012-diff-binary.sh
@@ -131,7 +131,7 @@ cat >expect <<EOF
 EOF
 
 test_expect_success 'diff --stat with binary files and big change count' '
-	echo X | dd of=binfile bs=1k seek=1 &&
+	printf "\01\00%1024d" 1 >binfile &&
 	git add binfile &&
 	i=0 &&
 	while test $i -lt 10000; do