diff --git a/src/Makefile.am b/src/Makefile.am
index 38d60af..57b8992 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -1,6 +1,14 @@
-noinst_LIBRARIES = libbip.a
+noinst_LIBRARIES = libbip.a libbiplex.a
 
-libbip_a_SOURCES = conf.y lex.l \
+libbiplex_a_SOURCES = \
+	conf.y lex.l
+
+# Not adding AM_CFLAGS here, because many debian flex releases generate code
+# that compares signed and unsigned integers. It looks like this issue is
+# fixed by flex 2.6.5 which is unreleased.
+libbiplex_a_CFLAGS = $(OPENSSL_CFLAGS)
+
+libbip_a_SOURCES = \
 	bip.c bip.h \
 	connection.c connection.h \
 	defaults.h \
@@ -19,11 +27,12 @@ bin_PROGRAMS = bip bipmkpw
 
 bip_SOURCES = bip_main.c
 bip_CFLAGS = ${OPENSSL_CFLAGS} $(AM_CFLAGS)
-bip_LDADD = libbip.a ${OPENSSL_LIBS}
-
+bip_LDADD = libbip.a libbiplex.a ${OPENSSL_LIBS}
 
 bipmkpw_SOURCES = bipmkpw.c md5.c util.c
 bipmkpw_CFLAGS = ${OPENSSL_CFLAGS} $(AM_CFLAGS)
+bipmkpw_LDADD = libbip.a libbiplex.a $(OPENSSL_LIBS)
+
 AM_YFLAGS= -d
 BUILT_SOURCES = conf.c conf.h lex.c
 
diff --git a/tests/Makefile.am b/tests/Makefile.am
index edb10e5..5700707 100644
--- a/tests/Makefile.am
+++ b/tests/Makefile.am
@@ -2,4 +2,4 @@ TESTS = check_line
 check_PROGRAMS = check_line
 check_line_SOURCES = check_line.c $(top_builddir)/src/line.h
 check_line_CFLAGS = @CHECK_CFLAGS@  $(OPENSSL_CFLAGS)
-check_line_LDADD = $(top_builddir)/src/libbip.a @CHECK_LIBS@  $(OPENSSL_LIBS)
+check_line_LDADD = $(top_builddir)/src/libbip.a $(top_builddir)/src/libbiplex.a @CHECK_LIBS@  $(OPENSSL_LIBS)