diff --git a/src/os/os_windows_test.go b/src/os/os_windows_test.go
index fb95499c17..d9c8fe3db9 100644
--- a/src/os/os_windows_test.go
+++ b/src/os/os_windows_test.go
@@ -990,6 +990,8 @@ func TestFileStatNUL(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
+	defer f.Close()
+
 	fi, err := f.Stat()
 	if err != nil {
 		t.Fatal(err)