diff --git a/gtp/Makefile.am b/gtp/Makefile.am
index 50c582c..77f81cf 100644
--- a/gtp/Makefile.am
+++ b/gtp/Makefile.am
@@ -6,10 +6,10 @@
 
 lib_LTLIBRARIES = libgtp.la
 
-include_HEADERS = gtp.h pdp.h gtpie.h
+include_HEADERS = gtp.h gsn.h pdp.h gtpie.h
 
 AM_CFLAGS = -O2 -fno-builtin -Wall -DSBINDIR='"$(sbindir)"' -ggdb $(LIBOSMOCORE_CFLAGS)
 
-libgtp_la_SOURCES = gtp.c gtp.h gtpie.c gtpie.h pdp.c pdp.h lookupa.c lookupa.h queue.c queue.h
+libgtp_la_SOURCES = gtp.c gtp.h gsn.c gsn.h gtpie.c gtpie.h pdp.c pdp.h lookupa.c lookupa.h queue.c queue.h
 libgtp_la_LDFLAGS = -version-info $(LIBVERSION) -no-undefined
 libgtp_la_LIBADD = $(LIBOSMOCORE_LIBS)