diff --git a/openbsc/src/libbsc/abis_nm.c b/openbsc/src/libbsc/abis_nm.c
index 0c3fff5..e6111f5 100644
--- a/openbsc/src/libbsc/abis_nm.c
+++ b/openbsc/src/libbsc/abis_nm.c
@@ -1712,7 +1712,10 @@
 			}
 		}
 	}
-	msgb_tv_put(msg, NM_ATT_TSC, bts->tsc);	/* training sequence */
+	if (ts->tsc == -1)
+		msgb_tv_put(msg, NM_ATT_TSC, bts->tsc);	/* training sequence */
+	else
+		msgb_tv_put(msg, NM_ATT_TSC, ts->tsc);	/* training sequence */
 	if (bts->type == GSM_BTS_TYPE_BS11)
 		msgb_tlv_put(msg, 0x59, 1, &zero);