Make without first installing gtplib
diff --git a/ggsn/Makefile.am b/ggsn/Makefile.am
index b72006e..8b84aea 100644
--- a/ggsn/Makefile.am
+++ b/ggsn/Makefile.am
@@ -2,7 +2,7 @@
 
 LDFLAGS = -Wl,--rpath -Wl,/usr/local/lib
 
-CFLAGS = -O2 -D_GNU_SOURCE -fno-builtin -Wall -ansi -DSBINDIR='"$(sbindir)"' -lgtp
+CFLAGS = -O2 -D_GNU_SOURCE -fno-builtin -Wall -ansi -DSBINDIR='"$(sbindir)"' -lgtp -L../gtp
 
 ggsn_SOURCES = ggsn.c tun.c tun.h cmdline.c cmdline.h