--- a/etc/pam/schroot
+++ b/etc/pam/schroot 
@@ -23,13 +23,9 @@
 # time restrainst on schroot usage.
 # account    requisite  pam_time.so
 
-# The standard Unix authentication modules, used with
-# NIS (man nsswitch) as well as normal /etc/passwd and
-# /etc/shadow entries.
-@include common-auth
-@include common-account
-@include common-session
-
+account required pam_unix.so
+session required pam_unix.so
+
 # Sets up user limits, please uncomment and read /etc/security/limits.conf
 # to enable this functionality.
 # session    required   pam_limits.so