diff --git a/configure.ac b/configure.ac
index 1bbcd79..588df6d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2,7 +2,7 @@
 
 AC_CONFIG_AUX_DIR(config)
 AC_CONFIG_HEADER([config.h])
-AM_INIT_AUTOMAKE([-Wall -Werror foreign])
+AM_INIT_AUTOMAKE([-Wall -Wno-extra-portability -Werror foreign])
 m4_ifdef([AM_PROG_AR], [AM_PROG_AR])
 LT_INIT
 AC_CONFIG_MACRO_DIR([m4])