diff --git a/builtin/diff-tree.c b/builtin/diff-tree.c
index 0e0ac1f1670..116097a404a 100644
--- a/builtin/diff-tree.c
+++ b/builtin/diff-tree.c
@@ -195,6 +195,7 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 		int saved_dcctc = 0;
 
 		opt->diffopt.rotate_to_strict = 0;
+		opt->diffopt.no_free = 1;
 		if (opt->diffopt.detect_rename) {
 			if (!the_index.cache)
 				repo_read_index(the_repository);
@@ -217,6 +218,8 @@ int cmd_diff_tree(int argc, const char **argv, const char *prefix)
 		}
 		opt->diffopt.degraded_cc_to_c = saved_dcctc;
 		opt->diffopt.needed_rename_limit = saved_nrl;
+		opt->diffopt.no_free = 0;
+		diff_free(&opt->diffopt);
 	}
 
 	return diff_result_code(&opt->diffopt, 0);
diff --git a/log-tree.c b/log-tree.c
index 38e5cccc1a1..3a03e34c305 100644
--- a/log-tree.c
+++ b/log-tree.c
@@ -1098,6 +1098,7 @@ int log_tree_commit(struct rev_info *opt, struct commit *commit)
 	opt->loginfo = &log;
 	opt->diffopt.no_free = 1;
 
+	/* NEEDSWORK: no restoring of no_free?  Why? */
 	if (opt->line_level_traverse)
 		return line_log_print(opt, commit);
 
diff --git a/t/t4013-diff-various.sh b/t/t4013-diff-various.sh
index 750aee17ea9..628b01f355a 100755
--- a/t/t4013-diff-various.sh
+++ b/t/t4013-diff-various.sh
@@ -542,6 +542,20 @@ test_expect_success 'diff-tree --stdin with log formatting' '
 	test_cmp expect actual
 '
 
+test_expect_success 'diff-tree --stdin with pathspec' '
+	cat >expect <<-EOF &&
+	Third
+
+	dir/sub
+	Second
+
+	dir/sub
+	EOF
+	git rev-list master^ |
+	git diff-tree -r --stdin --name-only --format=%s dir >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'diff -I<regex>: setup' '
 	git checkout master &&
 	test_seq 50 >file0 &&