Issue #3782: os.write() must not accept unicode strings
diff --git a/Lib/test/test_tempfile.py b/Lib/test/test_tempfile.py
index 5a81455..0e5cb0f 100644
--- a/Lib/test/test_tempfile.py
+++ b/Lib/test/test_tempfile.py
@@ -252,7 +252,7 @@
         # _mkstemp_inner can create files in a user-selected directory
         dir = tempfile.mkdtemp()
         try:
-            self.do_create(dir=dir).write("blat")
+            self.do_create(dir=dir).write(b"blat")
         finally:
             os.rmdir(dir)