-dnl SYLPHEED_CHECK_TYPE(TYPE, DEFAULT [, INCLUDES])
+dnl SYLPHEED_CHECK_TYPE(TYPE, DEFAULT [, INCLUDES, COMMENT])
dnl
dnl Like AC_CHECK_TYPE, but in addition to `sys/types.h', `stdlib.h' and
dnl `stddef.h' checks files included by INCLUDES, which should be a
dnl series of #include statements. If TYPE is not defined, define it
dnl to DEFAULT.
dnl
-AC_DEFUN(SYLPHEED_CHECK_TYPE,
+AC_DEFUN([SYLPHEED_CHECK_TYPE],
[AC_REQUIRE([AC_HEADER_STDC])dnl
AC_MSG_CHECKING(for $1)
AC_CACHE_VAL(sylpheed_cv_type_$1,