Match against correct version tag

Signed-off-by: Mike Marchetti <mmarchetti@sandvine.com>
diff --git a/setup.py b/setup.py
index 25a397c..bf1f71b 100644
--- a/setup.py
+++ b/setup.py
@@ -2,7 +2,8 @@
 
 setup(
     name='osmclient',
-    version_command=('git describe --tags --long --dirty', 'pep440-git'),
+    version_command=('git describe --match v* --tags --long --dirty',
+                     'pep440-git'),
     author='Mike Marchetti',
     author_email='mmarchetti@sandvine.com',
     packages=find_packages(),