diff --git a/setup.py b/setup.py
index 3279937..438ca88 100644
--- a/setup.py
+++ b/setup.py
@@ -9,13 +9,13 @@ if Cython.__version__ < '0.19.1':
     raise RuntimeError('Old cython installed. Please run `pip install -U cython`')
 
 from distutils.core import setup
+import os
 
 MAJOR = 0
 MINOR = 1
 MICRO = 0
 VERSION = '%d.%d.%d' % (MAJOR, MINOR, MICRO)
 
-
 def write_version_py(filename=None):
     cnt = """\
 version = '%s'
@@ -31,6 +31,8 @@ short_version = '%s'
     finally:
         a.close()
 
+write_version_py()
+
 setup(
     name="capnp",
     version=VERSION,