diff --git a/sql_array_types_roundtrip_test.go b/sql_array_types_roundtrip_test.go
index 888f4b0..4f903e6 100644
--- a/sql_array_types_roundtrip_test.go
+++ b/sql_array_types_roundtrip_test.go
@@ -36,7 +36,7 @@ type wrapped[T any] struct {
 
 // arrayRoundTrip runs the full Scan/Value/JSON/YAML/XML contract for one array type.
 // badScan is a literal the type's Scan must reject ("" skips the check).
-func arrayRoundTrip[T any, P arrayPtr[T]](t *testing.T, sample T, null T, badScan string) {
+func arrayRoundTrip[T any, P arrayPtr[T]](t *testing.T, sample, null T, badScan string) {
 	t.Helper()
 	sv, ok := any(sample).(arrayValue)
 	if !ok {