diff --git a/etc/mock/site-defaults.cfg b/etc/mock/site-defaults.cfg
index 8c2c6f6..62ff638 100644
--- a/etc/mock/site-defaults.cfg
+++ b/etc/mock/site-defaults.cfg
@@ -296,6 +296,10 @@
 # name in this line of the mock PAM config:
 #   auth  sufficient pam_succeed_if.so user ingroup mock use_uid quiet
 # config_opts['chrootgid'] = grp.getgrnam("mock")[2]
+# name of user that is used when executing commands inside the chroot
+# config_opts['chrootuser'] = 'mockbuild'
+# name of the group inside of chroot
+# config_opts['chrootgroup'] = 'mock'
 
 # config_opts['useradd'] = '/usr/sbin/useradd -m -u %(uid)s -g %(gid)s -d %(home)s -n %(user)s' # Fedora/RedHat
 #
diff --git a/py/mockbuild/buildroot.py b/py/mockbuild/buildroot.py
index 063fdf5..8c8299e 100644
--- a/py/mockbuild/buildroot.py
+++ b/py/mockbuild/buildroot.py
@@ -48,9 +48,9 @@ class Buildroot(object):
                         and util.selinuxEnabled())
 
         self.chrootuid = config['chrootuid']
-        self.chrootuser = 'mockbuild'
+        self.chrootuser = config['chrootuser']
         self.chrootgid = config['chrootgid']
-        self.chrootgroup = 'mockbuild'
+        self.chrootgroup = config['chrootgroup']
         self.env = config['environment']
         self.env['HOME'] = self.homedir
         proxy_env = util.get_proxy_environment(config)
diff --git a/py/mockbuild/util.py b/py/mockbuild/util.py
index 8e87a28..c3b0838 100644
--- a/py/mockbuild/util.py
+++ b/py/mockbuild/util.py
@@ -723,6 +723,8 @@ def setup_default_config_opts(unprivUid, version, pkgpythondir):
     except KeyError:
         #  'mock' group doesn't exist, must set in config file
         pass
+    config_opts['chrootgroup'] = 'mock'
+    config_opts['chrootuser'] = 'mockbuild'
     config_opts['build_log_fmt_name'] = "unadorned"
     config_opts['root_log_fmt_name'] = "detailed"
     config_opts['state_log_fmt_name'] = "state"