Installation of include files
diff --git a/gtp/Makefile.am b/gtp/Makefile.am
index 871a446..bacf365 100644
--- a/gtp/Makefile.am
+++ b/gtp/Makefile.am
@@ -1,5 +1,7 @@
 lib_LTLIBRARIES = libgtp.la
 
+include_HEADERS = gtp.h pdp.h
+
 CFLAGS = -O2 -fno-builtin -Wall -ansi -DSBINDIR='"$(sbindir)"' -ggdb
 
 libgtp_la_SOURCES = gtp.c gtp.h gtpie.c gtpie.h pdp.c pdp.h lookupa.c lookupa.h queue.c queue.h