diff --git a/include/osmocom/abis/e1_input.h b/include/osmocom/abis/e1_input.h
index c175649..8ef33d5 100644
--- a/include/osmocom/abis/e1_input.h
+++ b/include/osmocom/abis/e1_input.h
@@ -21,6 +21,7 @@
 	E1INP_SIGN_OSMO,	/* IPA CCM OSMO sub-type */
 };
 const char *e1inp_signtype_name(enum e1inp_sign_type tp);
+const struct value_string e1inp_sign_type_names[5];
 
 enum e1inp_ctr {
 	E1I_CTR_HDLC_ABORT,
@@ -65,6 +66,7 @@
 	E1INP_TS_TYPE_TRAU,
 };
 const char *e1inp_tstype_name(enum e1inp_ts_type tp);
+const struct value_string e1inp_ts_type_names[5];
 
 /* A timeslot in the E1 interface */
 struct e1inp_ts {