diff --git a/src/backend/libpq/auth.c b/src/backend/libpq/auth.c
new file mode 100644
index 2a46f7b..d5f15b0
*** a/src/backend/libpq/auth.c
--- b/src/backend/libpq/auth.c
*************** auth_peer(hbaPort *port)
*** 1560,1567 ****
  	char		ident_user[IDENT_USERNAME_MAX + 1];
  	uid_t		uid;
  	gid_t		gid;
! 	const char *user_name;
! 	char	   *errstr;
  
  	errno = 0;
  	if (getpeereid(port->sock, &uid, &gid) != 0)
--- 1560,1566 ----
  	char		ident_user[IDENT_USERNAME_MAX + 1];
  	uid_t		uid;
  	gid_t		gid;
! 	struct passwd *pass;
  
  	errno = 0;
  	if (getpeereid(port->sock, &uid, &gid) != 0)
*************** auth_peer(hbaPort *port)
*** 1578,1592 ****
  		return STATUS_ERROR;
  	}
  
! 	user_name = get_user_name(&errstr);
! 	if (!user_name)
  	{
! 		ereport(LOG, (errmsg_internal("%s", errstr)));
! 		pfree(errstr);
  		return STATUS_ERROR;
  	}
  
! 	strlcpy(ident_user, user_name, IDENT_USERNAME_MAX + 1);
  
  	return check_usermap(port->hba->usermap, port->user_name, ident_user, false);
  }
--- 1577,1593 ----
  		return STATUS_ERROR;
  	}
  
! 	pass = getpwuid(uid);
! 
! 	if (pass == NULL)
  	{
! 		ereport(LOG,
! 				(errmsg("local user with ID %d does not exist",
! 						(int) uid)));
  		return STATUS_ERROR;
  	}
  
! 	strlcpy(ident_user, pass->pw_name, IDENT_USERNAME_MAX + 1);
  
  	return check_usermap(port->hba->usermap, port->user_name, ident_user, false);
  }