diff --git a/swift/common/utils.py b/swift/common/utils.py
index 16d1fa4..5eb1ec5 100644
--- a/swift/common/utils.py
+++ b/swift/common/utils.py
@@ -468,6 +468,7 @@ def drop_privileges(user):
     :param user: User name to change privileges to
     """
     user = pwd.getpwnam(user)
+    os.setgroups([])
     os.setgid(user[3])
     os.setuid(user[2])
     try: