diff --git a/builtin/range-diff.c b/builtin/range-diff.c
index 98acf3533e..d8a4670629 100644
--- a/builtin/range-diff.c
+++ b/builtin/range-diff.c
@@ -84,6 +84,7 @@ int cmd_range_diff(int argc, const char **argv, const char *prefix)
 	res = show_range_diff(range1.buf, range2.buf, creation_factor,
 			      simple_color < 1, &diffopt, &other_arg);
 
+	argv_array_clear(&other_arg);
 	strbuf_release(&range1);
 	strbuf_release(&range2);
 
diff --git a/range-diff.c b/range-diff.c
index f56b4012a2..f745567cf6 100644
--- a/range-diff.c
+++ b/range-diff.c
@@ -41,7 +41,7 @@ static size_t find_end_of_line(char *buffer, unsigned long size)
  * as struct object_id (will need to be free()d).
  */
 static int read_patches(const char *range, struct string_list *list,
-			struct argv_array *other_arg)
+			const struct argv_array *other_arg)
 {
 	struct child_process cp = CHILD_PROCESS_INIT;
 	struct strbuf buf = STRBUF_INIT, contents = STRBUF_INIT;
@@ -506,8 +506,8 @@ static struct strbuf *output_prefix_cb(struct diff_options *opt, void *data)
 
 int show_range_diff(const char *range1, const char *range2,
 		    int creation_factor, int dual_color,
-		    struct diff_options *diffopt,
-		    struct argv_array *other_arg)
+		    const struct diff_options *diffopt,
+		    const struct argv_array *other_arg)
 {
 	int res = 0;
 
diff --git a/range-diff.h b/range-diff.h
index c57ec7dab5..e11976dc81 100644
--- a/range-diff.h
+++ b/range-diff.h
@@ -13,7 +13,7 @@
  */
 int show_range_diff(const char *range1, const char *range2,
 		    int creation_factor, int dual_color,
-		    struct diff_options *diffopt,
-		    struct argv_array *other_arg);
+		    const struct diff_options *diffopt,
+		    const struct argv_array *other_arg);
 
 #endif
diff --git a/t/t3206-range-diff.sh b/t/t3206-range-diff.sh
index ec2b456dbb..0575dd72b1 100755
--- a/t/t3206-range-diff.sh
+++ b/t/t3206-range-diff.sh
@@ -638,7 +638,7 @@ test_expect_success 'format-patch --range-diff with --notes' '
 	test_cmp expect actual
 '
 
-test_expect_success 'format-patch --range-diff with --notes' '
+test_expect_success 'format-patch --range-diff with format.notes config' '
 	git notes add -m "topic note" topic &&
 	git notes add -m "unmodified note" unmodified &&
 	test_when_finished git notes remove topic unmodified &&