diff --git a/optimizely/client.py b/optimizely/client.py
index 4480553..35ec576 100644
--- a/optimizely/client.py
+++ b/optimizely/client.py
@@ -32,7 +32,7 @@ def request(self, method, url_parts, headers=None, data=None):
         if method in self.ALLOWED_REQUESTS:
             # add request token header
             headers = headers or {}
-            headers.update({'Token': self.api_key})
+            headers.update({'Token': self.api_key, 'User-Agent': 'optimizely-client-python/0.1.1'})
 
             # make request and return parsed response
             url = urlparse.urljoin(self.api_base, '/'.join([str(url_part) for url_part in url_parts]))