diff --git a/contrib/subtree/t/t7900-subtree.sh b/contrib/subtree/t/t7900-subtree.sh
index ca4df5be83..c3bd2a58b9 100755
--- a/contrib/subtree/t/t7900-subtree.sh
+++ b/contrib/subtree/t/t7900-subtree.sh
@@ -63,7 +63,7 @@ test_create_pre2_32_repo () {
 	git -C "$1" log -1 --format=%B HEAD^2 >msg &&
 	test_commit -C "$1-sub" --annotate sub2 &&
 	git clone --no-local "$1" "$1-clone" &&
-	new_commit=$(cat msg | sed -e "s/$commit/$tag/" | git -C "$1-clone" commit-tree HEAD^2^{tree}) &&
+	new_commit=$(sed -e "s/$commit/$tag/" msg | git -C "$1-clone" commit-tree HEAD^2^{tree}) &&
 	git -C "$1-clone" replace HEAD^2 $new_commit
 }