DO_IPV6 fix.
diff --git a/extensions/Makefile b/extensions/Makefile
index 481e5fc..1ffba2a 100644
--- a/extensions/Makefile
+++ b/extensions/Makefile
@@ -17,9 +17,12 @@
 OPTIONALS+=$(patsubst %,IPv6:%,$(PF6_EXT_SLIB_OPTS))
 
 SHARED_LIBS+=$(foreach T,$(PF_EXT_SLIB),extensions/libipt_$(T).so)
-SHARED_LIBS+=$(foreach T,$(PF6_EXT_SLIB),extensions/libip6t_$(T).so)
 EXTRA_INSTALLS+=$(foreach T, $(PF_EXT_SLIB), $(DESTDIR)$(LIBDIR)/iptables/libipt_$(T).so)
+
+ifdef DO_IPV6
+SHARED_LIBS+=$(foreach T,$(PF6_EXT_SLIB),extensions/libip6t_$(T).so)
 EXTRA_INSTALLS+=$(foreach T, $(PF6_EXT_SLIB), $(DESTDIR)$(LIBDIR)/iptables/libip6t_$(T).so)
+endif
 
 ifndef TOPLEVEL_INCLUDED
 local: