diff --git a/openbsc/tests/channel/channel_test.c b/openbsc/tests/channel/channel_test.c
index ab0d9eb..e9badad 100644
--- a/openbsc/tests/channel/channel_test.c
+++ b/openbsc/tests/channel/channel_test.c
@@ -85,6 +85,7 @@
 
 void _abis_nm_sendmsg() {}
 void sms_alloc() {}
+void sms_free() {}
 void gsm_net_update_ctype(struct gsm_network *network) {}
 void gsm48_secure_channel() {}
 void paging_request_stop() {}