diff --git a/diff.c b/diff.c
index f72769a1c4..146521e194 100644
--- a/diff.c
+++ b/diff.c
@@ -1361,7 +1361,7 @@ static struct diffstat_file *diffstat_add(struct diffstat_t *diffstat,
 					  const char *name_b)
 {
 	struct diffstat_file *x;
-	x = xcalloc(sizeof (*x), 1);
+	x = xcalloc(1, sizeof(*x));
 	ALLOC_GROW(diffstat->files, diffstat->nr + 1, diffstat->alloc);
 	diffstat->files[diffstat->nr++] = x;
 	if (name_b) {