diff --git a/diff-no-index.c b/diff-no-index.c
index 2d541d9aba11ee69525a6a1ef5da6f8a61e9e65e..a3e47a76e401a1b98891b15a406b5806a294af3d 100644
--- a/diff-no-index.c
+++ b/diff-no-index.c
@@ -201,8 +201,6 @@ void diff_no_index(struct rev_info *revs,
 		    no_index ? "--no-index" : "[--no-index]");
 
 	diff_setup(&revs->diffopt);
-	if (!revs->diffopt.output_format)
-		revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 	for (i = 1; i < argc - 2; ) {
 		int j;
 		if (!strcmp(argv[i], "--no-index"))
@@ -248,6 +246,8 @@ void diff_no_index(struct rev_info *revs,
 		revs->diffopt.paths = argv + argc - 2;
 	revs->diffopt.nr_paths = 2;
 	revs->diffopt.skip_stat_unmatch = 1;
+	if (!revs->diffopt.output_format)
+		revs->diffopt.output_format = DIFF_FORMAT_PATCH;
 
 	DIFF_OPT_SET(&revs->diffopt, EXIT_WITH_STATUS);
 	DIFF_OPT_SET(&revs->diffopt, NO_INDEX);