diff --git a/openbsc/src/bsc_init.c b/openbsc/src/bsc_init.c
index 3e3f167..13a9677 100644
--- a/openbsc/src/bsc_init.c
+++ b/openbsc/src/bsc_init.c
@@ -1136,6 +1136,8 @@
 	/* Control Channel Description */
 	bts->si_common.chan_desc.att = 1;
 	bts->si_common.chan_desc.bs_pa_mfrms = RSL_BS_PA_MFRMS_5;
+	bts->si_common.chan_desc.bs_ag_blks_res = 1;
+
 	/* T3212 is set from vty/config */
 
 	/* Set ccch config by looking at ts config */