diff --git a/src/openvpn/Makefile.am b/src/openvpn/Makefile.am
index 4492c15..e80179c 100644
--- a/src/openvpn/Makefile.am
+++ b/src/openvpn/Makefile.am
@@ -57,6 +57,7 @@
 	dco_win.c dco_win.h \
 	dhcp.c dhcp.h \
 	dns.c dns.h \
+	domain_helper.h \
 	env_set.c env_set.h \
 	errlevel.h \
 	error.c error.h \