diff --git a/paramiko/_winapi.py b/paramiko/_winapi.py
index ab90c4a..b45a5d5 100644
--- a/paramiko/_winapi.py
+++ b/paramiko/_winapi.py
@@ -118,7 +118,7 @@ class MemoryMap(object):
 		FILE_MAP_WRITE = 0x2
 		filemap = ctypes.windll.kernel32.CreateFileMappingW(
 			INVALID_HANDLE_VALUE, p_SA, PAGE_READWRITE, 0, self.length,
-			unicode(self.name))
+			builtins.unicode(self.name))
 		handle_nonzero_success(filemap)
 		if filemap == INVALID_HANDLE_VALUE:
 			raise Exception("Failed to create file mapping")
diff --git a/paramiko/agent.py b/paramiko/agent.py
index d4ff703..920ea7f 100644
--- a/paramiko/agent.py
+++ b/paramiko/agent.py
@@ -215,7 +215,7 @@ class AgentClientProxy(object):
                 # probably a dangling env var: the ssh agent is gone
                 return
         elif sys.platform == 'win32':
-            import win_pageant
+            from paramiko import win_pageant
             if win_pageant.can_talk_to_agent():
                 conn = win_pageant.PageantConnection()
             else:
@@ -334,7 +334,7 @@ class Agent(AgentSSH):
                 # probably a dangling env var: the ssh agent is gone
                 return
         elif sys.platform == 'win32':
-            import win_pageant
+            from paramiko import win_pageant
             if win_pageant.can_talk_to_agent():
                 conn = win_pageant.PageantConnection()
             else:
diff --git a/paramiko/auth_handler.py b/paramiko/auth_handler.py
index c7bb58b..a935c70 100644
--- a/paramiko/auth_handler.py
+++ b/paramiko/auth_handler.py
@@ -25,6 +25,7 @@ import weakref
 
 # this helps freezing utils
 import encodings.utf_8
+import six
 
 from paramiko.common import *
 from paramiko import util
@@ -198,7 +199,7 @@ class AuthHandler (object):
             if self.auth_method == 'password':
                 m.add_boolean(False)
                 password = self.password
-                if isinstance(password, unicode):
+                if isinstance(password, six.text_type):
                     password = password.encode('UTF-8')
                 m.add_string(password)
             elif self.auth_method == 'publickey':
diff --git a/paramiko/client.py b/paramiko/client.py
index 002c04c..760edf5 100644
--- a/paramiko/client.py
+++ b/paramiko/client.py
@@ -25,6 +25,7 @@ import getpass
 import os
 import socket
 import warnings
+import six
 
 from paramiko.agent import Agent
 from paramiko.common import *
@@ -335,7 +336,7 @@ class SSHClient (object):
 
         if key_filename is None:
             key_filenames = []
-        elif isinstance(key_filename, (str, unicode)):
+        elif isinstance(key_filename, (six.binary_type, six.text_type)):
             key_filenames = [ key_filename ]
         else:
             key_filenames = key_filename
diff --git a/paramiko/server.py b/paramiko/server.py
index df1f7fc..1428929 100644
--- a/paramiko/server.py
+++ b/paramiko/server.py
@@ -21,6 +21,8 @@ L{ServerInterface} is an interface to override for server support.
 """
 
 import threading
+import six
+
 from paramiko.common import *
 from paramiko import util
 
@@ -48,7 +50,7 @@ class InteractiveQuery (object):
         self.instructions = instructions
         self.prompts = []
         for x in prompts:
-            if (type(x) is str) or (type(x) is unicode):
+            if isinstance(x, (six.binary_type, six.text_type)):
                 self.add_prompt(x)
             else:
                 self.add_prompt(x[0], x[1])
diff --git a/paramiko/sftp_client.py b/paramiko/sftp_client.py
index 07f5162..18bc39d 100644
--- a/paramiko/sftp_client.py
+++ b/paramiko/sftp_client.py
@@ -373,7 +373,7 @@ class SFTPClient (BaseSFTP):
         """
         dest = self._adjust_cwd(dest)
         self._log(DEBUG, 'symlink(%r, %r)' % (source, dest))
-        if type(source) is unicode:
+        if isinstance(source, six.text_type):
             source = source.encode('utf-8')
         self._request(CMD_SYMLINK, source, dest)
 
@@ -774,7 +774,7 @@ class SFTPClient (BaseSFTP):
         Return an adjusted path if we're emulating a "current working
         directory" for the server.
         """
-        if type(path) is unicode:
+        if isinstance(path, six.text_type):
             path = path.encode('utf-8')
         if self._cwd is None:
             return path
diff --git a/paramiko/transport.py b/paramiko/transport.py
index a561120..70773d7 100644
--- a/paramiko/transport.py
+++ b/paramiko/transport.py
@@ -280,7 +280,7 @@ class Transport (threading.Thread):
         @param sock: a socket or socket-like object to create the session over.
         @type sock: socket
         """
-        if isinstance(sock, (str, unicode)):
+        if isinstance(sock, (six.binary_type, six.text_type)):
             # convert "host:port" into (host, port)
             hl = sock.split(':', 1)
             if len(hl) == 1: