diff --git a/swift/common/utils.py b/swift/common/utils.py
index fc76be1e6d..de7384ca5b 100644
--- a/swift/common/utils.py
+++ b/swift/common/utils.py
@@ -17,6 +17,7 @@
 
 import errno
 import fcntl
+import grp
 import hmac
 import operator
 import os
@@ -1164,9 +1165,10 @@ def drop_privileges(user):
 
     :param user: User name to change privileges to
     """
-    user = pwd.getpwnam(user)
     if os.geteuid() == 0:
-        os.setgroups([])
+        groups = [g.gr_gid for g in grp.getgrall() if user in g.gr_mem]
+        os.setgroups(groups)
+    user = pwd.getpwnam(user)
     os.setgid(user[3])
     os.setuid(user[2])
     os.environ['HOME'] = user[5]
diff --git a/test/unit/common/test_utils.py b/test/unit/common/test_utils.py
index db2c9ba3bb..d84b2e09ae 100644
--- a/test/unit/common/test_utils.py
+++ b/test/unit/common/test_utils.py
@@ -21,6 +21,7 @@ import ctypes
 import errno
 import eventlet
 import eventlet.event
+import grp
 import logging
 import os
 import random
@@ -960,6 +961,10 @@ log_name = %(yarr)s'''
         import pwd
         self.assertEquals(pwd.getpwnam(user)[5], utils.os.environ['HOME'])
 
+        groups = [g.gr_gid for g in grp.getgrall() if user in g.gr_mem]
+        groups.append(pwd.getpwnam(user).pw_gid)
+        self.assertEquals(set(groups), set(os.getgroups()))
+
         # reset; test same args, OSError trying to get session leader
         utils.os = MockOs(called_funcs=required_func_calls,
                           raise_funcs=('setsid',))