diff --git a/include/Makefile.am b/include/Makefile.am
index b1a818d..42a2dc2 100644
--- a/include/Makefile.am
+++ b/include/Makefile.am
@@ -59,6 +59,7 @@
                        osmocom/gsm/mncc.h \
                        osmocom/gsm/prim.h \
                        osmocom/gsm/l1sap.h \
+                       osmocom/gsm/protocol/gsm_03_40.h \
                        osmocom/gsm/protocol/gsm_03_41.h \
                        osmocom/gsm/protocol/gsm_04_08.h \
                        osmocom/gsm/protocol/gsm_04_11.h \