diff --git a/Tests/test_file_jpeg2k.py b/Tests/test_file_jpeg2k.py
index fcd4b9d4d..db67e9551 100644
--- a/Tests/test_file_jpeg2k.py
+++ b/Tests/test_file_jpeg2k.py
@@ -52,7 +52,7 @@ class TestFileJpeg2k(PillowTestCase):
     def test_lossless(self):
         im = Image.open('Tests/images/test-card-lossless.jp2')
         im.load()
-        outfile = self.tempfile('test-card.png')
+        outfile = self.tempfile('temp_test-card.png')
         im.save(outfile)
         self.assert_image_similar(im, test_card, 1.0e-3)