diff --git a/Lib/test/test_uu.py b/Lib/test/test_uu.py
--- a/Lib/test/test_uu.py
+++ b/Lib/test/test_uu.py
@@ -191,16 +191,65 @@ class UUFileTest(unittest.TestCase):
             f = open(self.tmpout, 'rb')
             s = f.read()
             f.close()
             self.assertEqual(s, plaintext)
             # XXX is there an xp way to verify the mode?
         finally:
             self._kill(f)
 
+    def test_encode_defaults(self):
+        try:
+            with open(self.tmpin, 'wb') as f:
+                f.write(plaintext)
+
+            uu.encode(self.tmpin, self.tmpout)
+
+            with open(self.tmpout, 'rb') as f:
+                data = f.read()
+                self.assertEqual(data[26:-7], encodedtext)
+        finally:
+            self._kill(f)
+
+    @unittest.skipIf(
+        not hasattr(os, 'stat'),
+        "Skip on systems that don't support os.stat"
+                    )
+    def test_encode_osstat_assert(self):
+        try:
+            with open(self.tmpin, 'wb') as f:
+                f.write(plaintext)
+
+            _stat = os.stat
+            try:
+                del os.stat
+                uu.encode(self.tmpin, self.tmpout)
+            finally:
+                os.stat = _stat
+
+            with open(self.tmpout, 'rb') as f:
+                data = f.read()
+                self.assertEqual(int(str(data).split(' ')[1]),  666)
+        finally:
+            self._kill(f)
+
+    def test_encode_stdin_name(self):
+        try:
+            with open(self.tmpin, 'wb') as f:
+                f.write(plaintext)
+
+            with open(self.tmpin, 'rb') as f:
+                uu.encode(f, self.tmpout)
+
+            with open(self.tmpout, 'rb') as f:
+                data = f.read()
+                self.assertEqual(str(data).split(' ')[2][0], '-')
+        finally:
+            self._kill(f)
+
     def test_decode_filename(self):
         f = None
         try:
             support.unlink(self.tmpin)
             f = open(self.tmpin, 'wb')
             f.write(encodedtextwrapped(0o644, self.tmpout))
             f.close()
 
diff --git a/Lib/uu.py b/Lib/uu.py
--- a/Lib/uu.py
+++ b/Lib/uu.py
@@ -46,21 +46,24 @@ def encode(in_file, out_file, name=None,
     #
     opened_files = []
     try:
         if in_file == '-':
             in_file = sys.stdin.buffer
         elif isinstance(in_file, str):
             if name is None:
                 name = os.path.basename(in_file)
+            # Set defaults for mode
             if mode is None:
                 try:
-                    mode = os.stat(in_file).st_mode
+                    mode_stat = os.stat(in_file)
                 except AttributeError:
                     pass
+                else:
+                    mode = mode_stat.st_mode
             in_file = open(in_file, 'rb')
             opened_files.append(in_file)
         #
         # Open out_file if it is a pathname
         #
         if out_file == '-':
             out_file = sys.stdout.buffer
         elif isinstance(out_file, str):