diff --git a/ggsn/Makefile.am b/ggsn/Makefile.am
index 77aa013..0e99f50 100644
--- a/ggsn/Makefile.am
+++ b/ggsn/Makefile.am
@@ -6,5 +6,5 @@
 
 ggsn_LDADD = @LIBOBJS@
 
-ggsn_SOURCES = ggsn.c tun.c tun.h cmdline.c cmdline.h ippool.h ippool.c syserr.h syserr.c
+ggsn_SOURCES = ggsn.c tun.c tun.h cmdline.c cmdline.h ippool.h ippool.c syserr.h syserr.c lookup.c