diff --git a/python/trx/ctrl_if_bb.py b/python/trx/ctrl_if_bb.py
index b08f62c..77e02d0 100644
--- a/python/trx/ctrl_if_bb.py
+++ b/python/trx/ctrl_if_bb.py
@@ -22,6 +22,7 @@
 # with this program; if not, write to the Free Software Foundation, Inc.,
 # 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+import grgsm
 from ctrl_if import ctrl_if
 
 class ctrl_if_bb(ctrl_if):
@@ -107,14 +108,18 @@
 				return -1
 
 			# Ignore timeslot type for now
-			# Value 0 means 'drop all'
-			config = -1 if int(request[2]) == 0 else tn
-
+			config = int(request[2])
 			print("[i] Configure timeslot filter to: %s"
-				% ("drop all" if config == -1 else "TS %d" % tn))
+				% ("drop all" if config == 0 else "TS %d" % tn))
 
-			# HACK: configure built-in timeslot filter
-			self.tb.gsm_trx_if.ts_filter_set_tn(config)
+			if config == 0:
+				# Value 0 means 'drop all'
+				self.tb.gsm_ts_filter.set_policy(
+					grgsm.FILTER_POLICY_DROP_ALL)
+			else:
+				self.tb.gsm_ts_filter.set_policy(
+					grgsm.FILTER_POLICY_DEFAULT)
+				self.tb.gsm_ts_filter.set_tn(tn)
 
 			return 0
 
diff --git a/python/trx/radio_if.py b/python/trx/radio_if.py
index 661025a..5791f42 100644
--- a/python/trx/radio_if.py
+++ b/python/trx/radio_if.py
@@ -98,6 +98,9 @@
 		self.gsm_clck_ctrl = grgsm.clock_offset_control(
 			shift_fc, self.samp_rate, osr = 4)
 
+		self.gsm_ts_filter = grgsm.burst_timeslot_filter(0)
+		self.gsm_ts_filter.set_policy(grgsm.FILTER_POLICY_DROP_ALL)
+
 		self.gsm_trx_burst_if = grgsm.trx_burst_if(
 			self.trx_remote_addr, str(self.trx_base_port))
 
@@ -115,6 +118,9 @@
 			(self.gsm_input, 'ctrl_in'))
 
 		self.msg_connect((self.gsm_receiver, 'C0'),
+			(self.gsm_ts_filter, 'in'))
+
+		self.msg_connect((self.gsm_ts_filter, 'out'),
 			(self.gsm_trx_burst_if, 'bursts'))
 
 	def check_available(self):