diff --git a/t/helper/test-mergesort.c b/t/helper/test-mergesort.c
index 93d15d59a1..202e54a7ff 100644
--- a/t/helper/test-mergesort.c
+++ b/t/helper/test-mergesort.c
@@ -13,19 +13,10 @@ struct line {
 	struct line *next;
 };
 
-static void *get_next(const void *a)
-{
-	return ((const struct line *)a)->next;
-}
+DEFINE_LIST_SORT(static, sort_lines, struct line, next);
 
-static void set_next(void *a, void *b)
+static int compare_strings(const struct line *x, const struct line *y)
 {
-	((struct line *)a)->next = b;
-}
-
-static int compare_strings(const void *a, const void *b)
-{
-	const struct line *x = a, *y = b;
 	return strcmp(x->text, y->text);
 }
 
@@ -47,7 +38,7 @@ static int sort_stdin(void)
 		p = line;
 	}
 
-	lines = llist_mergesort(lines, get_next, set_next, compare_strings);
+	sort_lines(&lines, compare_strings);
 
 	while (lines) {
 		puts(lines->text);
diff --git a/t/perf/p0071-sort.sh b/t/perf/p0071-sort.sh
index ed366e2e12..ae4ddac864 100755
--- a/t/perf/p0071-sort.sh
+++ b/t/perf/p0071-sort.sh
@@ -40,11 +40,11 @@ done
 
 for file in unsorted sorted reversed
 do
-	test_perf "llist_mergesort() $file" "
+	test_perf "DEFINE_LIST_SORT $file" "
 		test-tool mergesort sort <$file >actual
 	"
 
-	test_expect_success "llist_mergesort() $file sorts like sort(1)" "
+	test_expect_success "DEFINE_LIST_SORT $file sorts like sort(1)" "
 		test_cmp_bin sorted actual
 	"
 done