Index: configure.ac
--- configure.ac.orig	2021-06-04 13:05:08.525160000 +0200
+++ configure.ac	2021-06-04 13:05:24.368703000 +0200
@@ -13,7 +13,7 @@
 
 AC_PREREQ([2.69])
 AC_INIT([libxo],[1.6.0],[phil@juniper.net])
-AM_INIT_AUTOMAKE([-Wall -Werror foreign -Wno-portability])
+AM_INIT_AUTOMAKE([foreign -Wno-portability])
 
 # Support silent build rules.  Requires at least automake-1.11.
 # Disable with "configure --disable-silent-rules" or "make V=1"
Index: libxo/xo.h
--- libxo/xo.h.orig	2020-01-23 23:45:49.000000000 +0100
+++ libxo/xo.h	2021-06-04 13:05:08.525629000 +0200
@@ -49,6 +49,8 @@
 #define PRINTFLIKE(_x, _y)
 #endif /* NO_PRINTFLIKE */
 
+#include <stdarg.h>
+
 /** Formatting types */
 typedef unsigned short xo_style_t;
 #define XO_STYLE_TEXT	0	/** Generate text output */
Index: warnings.mk
--- warnings.mk.orig	2014-08-30 04:46:54.000000000 +0200
+++ warnings.mk	2021-06-04 13:05:08.525835000 +0200
@@ -11,12 +11,9 @@
 # Commonly used sets of warnings
 #
 
-MIN_WARNINGS?= -W -Wall
+MIN_WARNINGS?=
 
-LOW_WARNINGS?= ${MIN_WARNINGS} \
-    -Wstrict-prototypes \
-    -Wmissing-prototypes \
-    -Wpointer-arith
+LOW_WARNINGS?= ${MIN_WARNINGS}
 
 MEDIUM_WARNINGS?= ${LOW_WARNINGS} -Werror