diff --git a/ccserver/utils.py b/ccserver/utils.py
index 0c70ae5f21699c579235bf234edac27392fc893d..e76900aa916ef048c887d5192db22f21e90d2272 100644
--- a/ccserver/utils.py
+++ b/ccserver/utils.py
@@ -27,7 +27,7 @@ class Acquires(object):
     '''
 
     def __init__(self, *locks):
-        self._locks = sorted(locks, key=lambda x: id(x))
+        self._locks = sorted(set(locks), key=lambda x: id(x))
 
     def __enter__(self):
         for lock in self._locks: