diff --git a/src/libmsc/gsm_04_08_cc.c b/src/libmsc/gsm_04_08_cc.c
index 5908db9..6148bbd 100644
--- a/src/libmsc/gsm_04_08_cc.c
+++ b/src/libmsc/gsm_04_08_cc.c
@@ -129,7 +129,7 @@
 
 /* Call Control */
 
-void cc_tx_to_mncc(struct gsm_network *net, struct msgb *msg)
+static void cc_tx_to_mncc(struct gsm_network *net, struct msgb *msg)
 {
 	net->mncc_recv(net, msg);
 }