diff --git a/README b/README
index 5fde85a..e4cb71e 100644
--- a/README
+++ b/README
@@ -2,14 +2,14 @@
 Installing PyMoira
 ==================
 
-To install PyMoira, you will first need to install Pyrex_. It's always
-a good idea to install Pyrex through your package manager, if
-possible. Your system's Pyrex package may be named ``python-pyrex`` or
-``pyrex-py25``. If your package manager doesn't have a package for
-Pyrex, or if you wish to install Pyrex by hand anyway, you can do so
+To install PyMoira, you will first need to install Cython_. It's
+always a good idea to install Cython through your package manager, if
+possible. Your system's Cython package may be named ``python3-cython``
+or ``py37-cython``. If your package manager doesn't have a package for
+Cython, or if you wish to install Cython by hand anyway, you can do so
 by running::
 
-  $ easy_install Pyrex
+  $ easy_install Cython
 
 Once you've done that, to install PyMoira globally, run::
 
@@ -33,7 +33,7 @@ build the Debian package of the latest release, run::
 
 You will need the devscripts and git-buildpackage packages installed,
 as well as this package's build dependencies (debhelper, cdbs,
-python-all-dev, python-support, python-pyrex, python-setuptools,
+python-all-dev, python-support, python-cython, python-setuptools,
 debathena-libmoira-dev).
 
-.. _Pyrex: http://www.cosc.canterbury.ac.nz/greg.ewing/python/Pyrex/
+.. _Cython: https://cython.org/
diff --git a/_moira.pyx b/_moira.pyx
index 80af823..acd3a39 100644
--- a/_moira.pyx
+++ b/_moira.pyx
@@ -1,3 +1,5 @@
+# cython: c_string_type=unicode, c_string_encoding=ascii
+
 cdef extern from "moira/moira.h":
     int mr_krb5_auth(char * prog)
     int mr_auth(char * prog)
@@ -57,6 +59,8 @@ def connect(server=''):
     if __connected:
         disconnect()
     
+    if isinstance(server, unicode):
+        server = server.encode('idna')
     status = mr_connect(server)
     if status != MR_SUCCESS:
         _error(status)
diff --git a/moira.py b/moira.py
index 7090a2d..2aa49b5 100644
--- a/moira.py
+++ b/moira.py
@@ -149,7 +149,7 @@ def access(handle, *args, **kwargs):
     try:
         _moira._access(handle, *args)
         return True
-    except MoiraException, e:
+    except MoiraException as e:
         if e.code != errors()['MR_PERM']:
             raise
         return False
diff --git a/qy b/qy
index baeccbb..ea52564 100755
--- a/qy
+++ b/qy
@@ -1,6 +1,8 @@
 #!/usr/bin/python
 """qy: A scriptable, command-line Moira client."""
 
+from __future__ import print_function
+
 import optparse
 
 import moira
@@ -53,8 +55,8 @@ def main():
         moira.auth(options.program)
 
     if args[0].startswith('_'):
-        print '\n'.join(', '.join(x) for x in
-                        moira._list_query(*args))
+        print('\n'.join(', '.join(x) for x in
+                        moira._list_query(*args)))
     else:
         results = moira.query(fmt=tuple, *args)
 
@@ -63,10 +65,10 @@ def main():
             r = filter_fields(r, options.fields)
 
             if options.single:
-                print ', '.join(v for (k, v) in r)
+                print(', '.join(v for (k, v) in r))
             else:
                 for k, v in r:
-                    print '%-*s: %s' % (keylen, k, v)
+                    print('%-*s: %s' % (keylen, k, v))
                 print
 
 if __name__ == '__main__':
diff --git a/setup.py b/setup.py
index ff2db53..e196831 100755
--- a/setup.py
+++ b/setup.py
@@ -2,24 +2,23 @@
 
 from setuptools import setup
 from distutils.extension import Extension
-from Pyrex.Distutils import build_ext
+from Cython.Build import cythonize
 
 setup(
     name="PyMoira",
-    version="4.3.0",
+    version="4.3.1",
     description="PyMoira - Python bindings for the Athena Moira library",
     author="Evan Broder",
     author_email="broder@mit.edu",
     license="MIT",
     py_modules=['moira'],
-    ext_modules=[
+    ext_modules=cythonize([
         Extension("_moira",
                   ["_moira.pyx"],
                   libraries=["moira", "krb5"]),
         Extension("mrclient",
                   ["mrclient.pyx"],
                   libraries=["mrclient", "moira"]),
-        ],
+    ]),
     scripts=['qy'],
-    cmdclass= {"build_ext": build_ext}
 )