diff --git a/git-merge-one-file.sh b/git-merge-one-file.sh
index d067894bf4..bb64a72ad3 100755
--- a/git-merge-one-file.sh
+++ b/git-merge-one-file.sh
@@ -22,6 +22,11 @@ LONG_USAGE="Usage: git merge-one-file $USAGE
 
 Blob ids and modes should be empty for missing files."
 
+SUBDIRECTORY_OK=Yes
+. git-sh-setup
+cd_to_toplevel
+require_work_tree
+
 if ! test "$#" -eq 7
 then
 	echo "$LONG_USAGE"
@@ -132,7 +137,7 @@ case "${1:-.}${2:-.}${3:-.}" in
 
 	# Create the working tree file, using "our tree" version from the
 	# index, and then store the result of the merge.
-	git checkout-index -f --stage=2 -- "$4" && cat "$src1" >"$4"
+	git checkout-index -f --stage=2 -- "$4" && cat "$src1" >"$4" || exit 1
 	rm -f -- "$orig" "$src1" "$src2"
 
 	if [ "$6" != "$7" ]; then
diff --git a/t/t6060-merge-index.sh b/t/t6060-merge-index.sh
index 895f079c92..debadbd299 100755
--- a/t/t6060-merge-index.sh
+++ b/t/t6060-merge-index.sh
@@ -68,7 +68,7 @@ test_expect_success 'merge-one-file fails without a work tree' '
 	)
 '
 
-test_expect_failure 'merge-one-file respects GIT_WORK_TREE' '
+test_expect_success 'merge-one-file respects GIT_WORK_TREE' '
 	(cd bare.git &&
 	 mkdir work &&
 	 GIT_WORK_TREE=$PWD/work &&
@@ -82,7 +82,7 @@ test_expect_failure 'merge-one-file respects GIT_WORK_TREE' '
 	test_cmp expect-merged bare.git/work/file-index
 '
 
-test_expect_failure 'merge-one-file respects core.worktree' '
+test_expect_success 'merge-one-file respects core.worktree' '
 	mkdir subdir &&
 	git clone . subdir/child &&
 	(cd subdir &&