diff --git a/Makefile.am b/Makefile.am
index f17c314..719f73d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -14,7 +14,7 @@ src_bipmkpw_SOURCES = src/bipmkpw.c src/md5.c src/util.c
 AM_YFLAGS= -d
 BUILT_SOURCES = src/conf.c src/conf.h src/lex.c
 
-AM_CFLAGS=-Wall -Wextra
+AM_CFLAGS=-Wall -Wextra -Werror
 
 dist_man_MANS = bip.1 bip.conf.5 bipmkpw.1