diff --git a/include/osmocom/bsc/lchan_fsm.h b/include/osmocom/bsc/lchan_fsm.h
index 35b88471e..9fbf9b3dc 100644
--- a/include/osmocom/bsc/lchan_fsm.h
+++ b/include/osmocom/bsc/lchan_fsm.h
@@ -14,6 +14,7 @@
 
 enum lchan_fsm_state {
 	LCHAN_ST_UNUSED,
+	LCHAN_ST_CBCH, /*< Blocked by CBCH channel combination, not usable as SDCCH. */
 	LCHAN_ST_WAIT_TS_READY,
 	LCHAN_ST_WAIT_ACTIV_ACK, /*< After RSL Chan Act Ack, lchan is active but RTP not configured. */
 	LCHAN_ST_WAIT_RLL_RTP_ESTABLISH,
diff --git a/src/osmo-bsc/lchan_fsm.c b/src/osmo-bsc/lchan_fsm.c
index 1ef7869d3..c80d8a16e 100644
--- a/src/osmo-bsc/lchan_fsm.c
+++ b/src/osmo-bsc/lchan_fsm.c
@@ -1035,6 +1035,13 @@ static const struct osmo_fsm_state lchan_fsm_states[] = {
 			,
 		.out_state_mask = 0
 			| S(LCHAN_ST_WAIT_TS_READY)
+			| S(LCHAN_ST_CBCH)
+			,
+	},
+	[LCHAN_ST_CBCH] = {
+		.name = "CBCH",
+		.out_state_mask = 0
+			| S(LCHAN_ST_UNUSED)
 			,
 	},
 	[LCHAN_ST_WAIT_TS_READY] = {
diff --git a/src/osmo-bsc/timeslot_fsm.c b/src/osmo-bsc/timeslot_fsm.c
index 56b335773..fc2546003 100644
--- a/src/osmo-bsc/timeslot_fsm.c
+++ b/src/osmo-bsc/timeslot_fsm.c
@@ -295,6 +295,15 @@ static void ts_fsm_unused_onenter(struct osmo_fsm_inst *fi, uint32_t prev_state)
 					T_CHAN_ACT_DEACT);
 		break;
 
+	case GSM_PCHAN_CCCH_SDCCH4_CBCH:
+	case GSM_PCHAN_SDCCH8_SACCH8C_CBCH:
+		/* For any pchans containing a CBCH, lchan[2] is reserved for CBCH and cannot be
+		 * allocated for SDCCH. */
+		OSMO_ASSERT(ts->lchan[2].fi);
+		ts->lchan[2].type = GSM_LCHAN_CBCH;
+		osmo_fsm_inst_state_chg(ts->lchan[2].fi, LCHAN_ST_CBCH, 0, 0);
+		break;
+
 	default:
 		/* nothing to do */
 		break;