diff --git a/src/gsm/libosmogsm.map b/src/gsm/libosmogsm.map
index e9a9e4f..dc4e0a6 100644
--- a/src/gsm/libosmogsm.map
+++ b/src/gsm/libosmogsm.map
@@ -183,6 +183,7 @@
 gsm0808_create_handover_failure;
 gsm0808_create_handover_performed;
 gsm0808_prepend_dtap_header;
+gsm0808_enc_cause;
 gsm0808_enc_aoip_trasp_addr;
 gsm0808_dec_aoip_trasp_addr;
 gsm0808_enc_speech_codec;