diff --git a/openbsc/src/libmsc/Makefile.am b/openbsc/src/libmsc/Makefile.am
index 2b50599..1e58cd1 100644
--- a/openbsc/src/libmsc/Makefile.am
+++ b/openbsc/src/libmsc/Makefile.am
@@ -6,7 +6,8 @@
 
 libmsc_a_SOURCES =	auth.c \
 			db.c \
-			gsm_04_08.c gsm_04_11.c gsm_04_80.c \
+			gsm_04_08.c gsm_04_11.c gsm_04_11_helper.c \
+			gsm_04_80.c \
 			gsm_subscriber.c \
 			mncc.c mncc_builtin.c mncc_sock.c \
 			rrlp.c \