diff --git a/include/osmocore/gsm0808.h b/include/osmocore/gsm0808.h
index a40713f..9166e54 100644
--- a/include/osmocore/gsm0808.h
+++ b/include/osmocore/gsm0808.h
@@ -36,6 +36,8 @@
 						 uint8_t speech_mode);
 struct msgb *gsm0808_create_assignment_failure(uint8_t cause, uint8_t *rr_cause);
 
+void gsm0808_prepend_dtap_header(struct msgb *msg, uint8_t link_id);
+
 const struct tlv_definition *gsm0808_att_tlvdef();
 
 #endif