--- a/setup.py
+++ b/setup.py
@@ -64,7 +64,8 @@ setup(name='mercurial',
packages=['mercurial', 'mercurial.hgweb', 'hgext', 'hgext.convert'],
ext_modules=[Extension('mercurial.mpatch', ['mercurial/mpatch.c']),
Extension('mercurial.bdiff', ['mercurial/bdiff.c']),
- Extension('mercurial.base85', ['mercurial/base85.c'])],
+ Extension('mercurial.base85', ['mercurial/base85.c']),
+ Extension('mercurial.diffhelpers', ['mercurial/diffhelpers.c'])],
data_files=[(os.path.join('mercurial', root),
[os.path.join(root, file_) for file_ in files])
for root, dirs, files in os.walk('templates')],