diff --git a/src/wormhole/cli/cli.py b/src/wormhole/cli/cli.py
index 33e7442..ba5ec2c 100644
--- a/src/wormhole/cli/cli.py
+++ b/src/wormhole/cli/cli.py
@@ -3,6 +3,7 @@ from __future__ import print_function
 import os
 import time
 start = time.time()
+import six
 from textwrap import fill, dedent
 from sys import stdout, stderr
 from . import public_relay
@@ -106,28 +107,28 @@ def _dispatch_command(reactor, cfg, command):
         yield maybeDeferred(command)
     except (WrongPasswordError, KeyFormatError, NoTorError) as e:
         msg = fill("ERROR: " + dedent(e.__doc__))
-        print(msg, file=stderr)
+        print(msg, file=cfg.stderr)
         raise SystemExit(1)
     except WelcomeError as e:
         msg = fill("ERROR: " + dedent(e.__doc__))
-        print(msg, file=stderr)
-        print(file=stderr)
-        print(str(e), file=stderr)
+        print(msg, file=cfg.stderr)
+        print(six.u(""), file=cfg.stderr)
+        print(six.text_type(e), file=cfg.stderr)
         raise SystemExit(1)
     except TransferError as e:
-        print("TransferError: %s" % str(e), file=stderr)
+        print(u"TransferError: %s" % six.text_type(e), file=cfg.stderr)
         raise SystemExit(1)
     except Exception as e:
         # this prints a proper traceback, whereas
         # traceback.print_exc() just prints a TB to the "yield"
         # line above ...
-        Failure().printTraceback(file=stderr)
-        print("ERROR:", e, file=stderr)
+        Failure().printTraceback(file=cfg.stderr)
+        print(u"ERROR:", six.text_type(e), file=cfg.stderr)
         raise SystemExit(1)
 
     cfg.timing.add("exit")
     if cfg.dump_timing:
-        cfg.timing.write(cfg.dump_timing, stderr)
+        cfg.timing.write(cfg.dump_timing, cfg.stderr)
 
 
 CommonArgs = _compose(
diff --git a/src/wormhole/test/test_cli.py b/src/wormhole/test/test_cli.py
index 353fa34..7aba918 100644
--- a/src/wormhole/test/test_cli.py
+++ b/src/wormhole/test/test_cli.py
@@ -1,5 +1,6 @@
 from __future__ import print_function, unicode_literals
 import os, sys, re, io, zipfile, six, stat
+from textwrap import fill, dedent
 from humanize import naturalsize
 import mock
 from twisted.trial import unittest
@@ -9,7 +10,7 @@ from twisted.internet.utils import getProcessOutputAndValue
 from twisted.internet.defer import gatherResults, inlineCallbacks, returnValue
 from .. import __version__
 from .common import ServerBase, config
-from ..cli import cmd_send, cmd_receive, welcome
+from ..cli import cmd_send, cmd_receive, welcome, cli
 from ..errors import TransferError, WrongPasswordError, WelcomeError
 
 
@@ -989,3 +990,81 @@ class Welcome(unittest.TestCase):
     def test_motd(self):
         stderr = self.do({"motd": "hello"})
         self.assertEqual(stderr, "Server (at url) says:\n hello\n")
+
+class Dispatch(unittest.TestCase):
+    @inlineCallbacks
+    def test_success(self):
+        cfg = config("send")
+        cfg.stderr = io.StringIO()
+        called = []
+        def fake():
+            called.append(1)
+        yield cli._dispatch_command(reactor, cfg, fake)
+        self.assertEqual(called, [1])
+        self.assertEqual(cfg.stderr.getvalue(), "")
+
+    @inlineCallbacks
+    def test_timing(self):
+        cfg = config("send")
+        cfg.stderr = io.StringIO()
+        cfg.timing = mock.Mock()
+        cfg.dump_timing = "filename"
+        def fake():
+            pass
+        yield cli._dispatch_command(reactor, cfg, fake)
+        self.assertEqual(cfg.stderr.getvalue(), "")
+        self.assertEqual(cfg.timing.mock_calls[-1],
+                         mock.call.write("filename", cfg.stderr))
+
+    @inlineCallbacks
+    def test_wrong_password_error(self):
+        cfg = config("send")
+        cfg.stderr = io.StringIO()
+        def fake():
+            raise WrongPasswordError("abcd")
+        yield self.assertFailure(cli._dispatch_command(reactor, cfg, fake),
+                                 SystemExit)
+        expected = fill("ERROR: " + dedent(WrongPasswordError.__doc__))+"\n"
+        self.assertEqual(cfg.stderr.getvalue(), expected)
+
+    @inlineCallbacks
+    def test_welcome_error(self):
+        cfg = config("send")
+        cfg.stderr = io.StringIO()
+        def fake():
+            raise WelcomeError("abcd")
+        yield self.assertFailure(cli._dispatch_command(reactor, cfg, fake),
+                                 SystemExit)
+        expected = fill("ERROR: " + dedent(WelcomeError.__doc__))+"\n\nabcd\n"
+        self.assertEqual(cfg.stderr.getvalue(), expected)
+
+    @inlineCallbacks
+    def test_transfer_error(self):
+        cfg = config("send")
+        cfg.stderr = io.StringIO()
+        def fake():
+            raise TransferError("abcd")
+        yield self.assertFailure(cli._dispatch_command(reactor, cfg, fake),
+                                 SystemExit)
+        expected = "TransferError: abcd\n"
+        self.assertEqual(cfg.stderr.getvalue(), expected)
+
+    @inlineCallbacks
+    def test_other_error(self):
+        cfg = config("send")
+        cfg.stderr = io.StringIO()
+        def fake():
+            raise ValueError("abcd")
+        # I'm seeing unicode problems with the Failure().printTraceback, and
+        # the output would be kind of unpredictable anyways, so we'll mock it
+        # out here.
+        f = mock.Mock()
+        def mock_print(file):
+            file.write("<TRACEBACK>\n")
+        f.printTraceback = mock_print
+        with mock.patch("wormhole.cli.cli.Failure", return_value=f):
+            yield self.assertFailure(cli._dispatch_command(reactor, cfg, fake),
+                                     SystemExit)
+        expected = "<TRACEBACK>\nERROR: abcd\n"
+        self.assertEqual(cfg.stderr.getvalue(), expected)
+