diff --git a/t/t7507-commit-verbose.sh b/t/t7507-commit-verbose.sh
index a3c8582577..5a811812f0 100755
--- a/t/t7507-commit-verbose.sh
+++ b/t/t7507-commit-verbose.sh
@@ -3,11 +3,10 @@
 test_description='verbose commit template'
 . ./test-lib.sh
 
-cat >check-for-diff <<EOF
-#!$SHELL_PATH
-exec grep '^diff --git' "\$1"
+write_script "check-for-diff" <<\EOF &&
+grep '^diff --git' "$1" >out
+exit 0
 EOF
-chmod +x check-for-diff
 test_set_editor "$PWD/check-for-diff"
 
 cat >message <<'EOF'
@@ -23,7 +22,8 @@ test_expect_success 'setup' '
 '
 
 test_expect_success 'initial commit shows verbose diff' '
-	git commit --amend -v
+	git commit --amend -v &&
+	test_line_count = 1 out
 '
 
 test_expect_success 'second commit' '
@@ -39,13 +39,15 @@ check_message() {
 
 test_expect_success 'verbose diff is stripped out' '
 	git commit --amend -v &&
-	check_message message
+	check_message message &&
+	test_line_count = 1 out
 '
 
 test_expect_success 'verbose diff is stripped out (mnemonicprefix)' '
 	git config diff.mnemonicprefix true &&
 	git commit --amend -v &&
-	check_message message
+	check_message message &&
+	test_line_count = 1 out
 '
 
 cat >diff <<'EOF'