diff --git a/auth/auth.py b/auth/auth.py
index 11680cfee..9c6281aef 100644
--- a/auth/auth.py
+++ b/auth/auth.py
@@ -29,7 +29,7 @@ def process_basic_auth(auth):
     logger.debug('Invalid basic auth format.')
     return
 
-  credentials = b64decode(normalized[1]).split(':')
+  credentials = b64decode(normalized[1]).split(':', 1)
 
   if len(credentials) != 2:
     logger.debug('Invalid basic auth credential format.')