diff --git a/plumbum/cli.py b/plumbum/cli.py
index 5112c7613..38f7f2c01 100644
--- a/plumbum/cli.py
+++ b/plumbum/cli.py
@@ -126,7 +126,7 @@ def set_terse(self):
 
     :returns: The decorated function (with a ``_switch_info`` attribute)
     """
-    if isinstance(names, basestring):
+    if isinstance(names, six.string_types):
         names = [names]
     names = [n.lstrip("-") for n in names]
     requires = [n.lstrip("-") for n in requires]
diff --git a/plumbum/commands.py b/plumbum/commands.py
index 5a5ca3905..3b614a32a 100644
--- a/plumbum/commands.py
+++ b/plumbum/commands.py
@@ -292,7 +292,7 @@ def _get_encoding(self):
     def formulate(self, level = 0, args = ()):
         return self.cmd.formulate(level + 1, self.args + tuple(args))
     def popen(self, args = (), **kwargs):
-        if isinstance(args, basestring):
+        if isinstance(args, six.string_types):
             args = (args,)
         return self.cmd.popen(self.args + tuple(args), **kwargs)
 
@@ -345,7 +345,7 @@ def popen(self, args = (), **kwargs):
 
         if self.KWARG in kwargs and kwargs[self.KWARG] not in (PIPE, None):
             raise RedirectionError("%s is already redirected" % (self.KWARG,))
-        if isinstance(self.file, (basestring, LocalPath)):
+        if isinstance(self.file, six.string_types + (LocalPath,)):
             f = kwargs[self.KWARG] = open(str(self.file), self.MODE)
         elif isinstance(self.file, RemotePath):
             raise TypeError("Cannot redirect to/from remote paths")
diff --git a/plumbum/local_machine.py b/plumbum/local_machine.py
index a1487a1c6..2afd62c77 100644
--- a/plumbum/local_machine.py
+++ b/plumbum/local_machine.py
@@ -8,6 +8,7 @@
 import stat
 import time
 import platform
+import six
 from tempfile import mkdtemp
 from subprocess import Popen, PIPE
 from contextlib import contextmanager
@@ -421,7 +422,7 @@ def __repr__(self):
         return "LocalCommand(%r)" % (self.executable,)
 
     def popen(self, args = (), cwd = None, env = None, **kwargs):
-        if isinstance(args, basestring):
+        if isinstance(args, six.string_types):
             args = (args,)
         return local._popen(self.executable, self.formulate(0, args),
             cwd = self.cwd if cwd is None else cwd, env = self.env if env is None else env,
diff --git a/plumbum/remote_path.py b/plumbum/remote_path.py
index 2ca1a2e55..8b72c0911 100644
--- a/plumbum/remote_path.py
+++ b/plumbum/remote_path.py
@@ -138,7 +138,7 @@ def delete(self):
     def move(self, dst):
         if isinstance(dst, RemotePath) and dst.remote is not self.remote:
             raise TypeError("dst points to a different remote machine")
-        elif not isinstance(dst, basestring):
+        elif not isinstance(dst, six.string_types):
             raise TypeError("dst must be a string or a RemotePath (to the same remote machine)")
         self.remote._session.run("mv %s %s" % (shquote(self), shquote(dst)))
 
@@ -147,10 +147,10 @@ def copy(self, dst, override = False):
         if isinstance(dst, RemotePath):
             if dst.remote is not self.remote:
                 raise TypeError("dst points to a different remote machine")
-        elif not isinstance(dst, basestring):
+        elif not isinstance(dst, six.string_types):
             raise TypeError("dst must be a string or a RemotePath (to the same remote machine)", repr(dst))
         if override:
-            if isinstance(dst, basestring):
+            if isinstance(dst, six.string_types):
                 dst = RemotePath(self.remote, dst)
             dst.remove()
         self.remote._session.run("cp -r %s %s" % (shquote(self), shquote(dst)))
diff --git a/plumbum/utils.py b/plumbum/utils.py
index 4b7d47cba..d121ae951 100644
--- a/plumbum/utils.py
+++ b/plumbum/utils.py
@@ -1,4 +1,5 @@
 from __future__ import with_statement
+import six
 from plumbum.path import Path
 from plumbum.local_machine import local, LocalPath
 
@@ -11,7 +12,7 @@ def delete(*paths):
     for p in paths:
         if isinstance(p, Path):
             p.delete()
-        elif isinstance(p, basestring):
+        elif isinstance(p, six.string_types):
             local.path(p).delete()
         elif hasattr(p, "__iter__"):
             delete(*p)