diff --git a/include/osmocom/gsm/abis_nm.h b/include/osmocom/gsm/abis_nm.h
index 4682ead..86b97eb 100644
--- a/include/osmocom/gsm/abis_nm.h
+++ b/include/osmocom/gsm/abis_nm.h
@@ -30,6 +30,7 @@
 const char *abis_nm_opstate_name(uint8_t os);
 const char *abis_nm_avail_name(uint8_t avail);
 const char *abis_nm_test_name(uint8_t test);
+extern const struct tlv_definition abis_nm_osmo_att_tlvdef;
 
 /*! \brief write a human-readable OML header to the debug log
  *  \param[in] ss Logging sub-system