diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py
index 518005aadaf..635c828d55e 100644
--- a/Lib/test/test_bz2.py
+++ b/Lib/test/test_bz2.py
@@ -243,7 +243,7 @@ class BZ2FileTest(BaseTest):
         self.createTempFile()
         bz2f = BZ2File(self.filename, "U")
         bz2f.close()
-        f = open(self.filename)
+        f = open(self.filename, "rb")
         f.seek(0, 2)
         self.assertEqual(f.tell(), len(self.DATA))
         f.close()