diff --git a/src/encoding.cpp b/src/encoding.cpp
index 8ec0be5..0afd55d 100644
--- a/src/encoding.cpp
+++ b/src/encoding.cpp
@@ -543,7 +543,6 @@
 
 /* generate uplink assignment */
 void Encoding::write_packet_uplink_assignment(
-	struct gprs_rlcmac_bts *bts,
 	bitvec * dest, uint8_t old_tfi,
 	uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
 	struct gprs_rlcmac_ul_tbf *tbf, uint8_t poll, uint8_t rrbp, uint8_t alpha,
@@ -787,7 +786,7 @@
 }
 
 static void write_packet_ack_nack_desc_gprs(
-	struct gprs_rlcmac_bts *bts, bitvec * dest, unsigned& wp,
+	bitvec * dest, unsigned& wp,
 	gprs_rlc_ul_window *window, bool is_final)
 {
 	char rbb[65];
@@ -809,12 +808,12 @@
 }
 
 static void write_packet_uplink_ack_gprs(
-	struct gprs_rlcmac_bts *bts, bitvec * dest, unsigned& wp,
+	bitvec * dest, unsigned& wp,
 	struct gprs_rlcmac_ul_tbf *tbf, bool is_final)
 {
 
 	bitvec_write_field(dest, &wp, mcs_chan_code(tbf->current_cs()), 2); // CHANNEL_CODING_COMMAND
-	write_packet_ack_nack_desc_gprs(bts, dest, wp, tbf->window(), is_final);
+	write_packet_ack_nack_desc_gprs(dest, wp, tbf->window(), is_final);
 
 	bitvec_write_field(dest, &wp, 1, 1); // 1: have CONTENTION_RESOLUTION_TLLI
 	bitvec_write_field(dest, &wp, tbf->tlli(), 32); // CONTENTION_RESOLUTION_TLLI
@@ -830,7 +829,7 @@
 };
 
 static void write_packet_ack_nack_desc_egprs(
-	struct gprs_rlcmac_bts *bts, bitvec * dest, unsigned& wp,
+	bitvec * dest, unsigned& wp,
 	gprs_rlc_ul_window *window, bool is_final, unsigned& rest_bits)
 {
 	unsigned int urbb_len = 0;
@@ -987,7 +986,7 @@
 }
 
 static void write_packet_uplink_ack_egprs(
-	struct gprs_rlcmac_bts *bts, bitvec * dest, unsigned& wp,
+	bitvec * dest, unsigned& wp,
 	struct gprs_rlcmac_ul_tbf *tbf, bool is_final)
 {
 	bitvec_write_field(dest, &wp, 0, 2); // fixed 00
@@ -1009,15 +1008,14 @@
 
 	/* -2 for last bit 0 mandatory and REL5 not supported */
 	unsigned bits_ack_nack = dest->data_len * 8 - wp - 2;
-	write_packet_ack_nack_desc_egprs(bts, dest, wp, tbf->window(), is_final, bits_ack_nack);
+	write_packet_ack_nack_desc_egprs(dest, wp, tbf->window(), is_final, bits_ack_nack);
 
 	bitvec_write_field(dest, &wp, 0, 1); // fixed 0
 	bitvec_write_field(dest, &wp, 0, 1); // 0: don't have REL 5
 };
 
 void Encoding::write_packet_uplink_ack(
-	struct gprs_rlcmac_bts *bts, bitvec * dest,
-	struct gprs_rlcmac_ul_tbf *tbf, bool is_final,
+	bitvec * dest, struct gprs_rlcmac_ul_tbf *tbf, bool is_final,
 	uint8_t rrbp)
 {
 	unsigned wp = 0;
@@ -1038,11 +1036,11 @@
 	if (tbf->is_egprs_enabled()) {
 		/* PU_AckNack_EGPRS = on */
 		bitvec_write_field(dest, &wp, 1, 1);  // 1: EGPRS
-		write_packet_uplink_ack_egprs(bts, dest, wp, tbf, is_final);
+		write_packet_uplink_ack_egprs(dest, wp, tbf, is_final);
 	} else {
 		/* PU_AckNack_GPRS = on */
 		bitvec_write_field(dest, &wp, 0, 1);  // 0: GPRS
-		write_packet_uplink_ack_gprs(bts, dest, wp, tbf, is_final);
+		write_packet_uplink_ack_gprs(dest, wp, tbf, is_final);
 	}
 
 	LOGP(DRLCMACUL, LOGL_DEBUG,
diff --git a/src/encoding.h b/src/encoding.h
index 2309dc3..6dcced0 100644
--- a/src/encoding.h
+++ b/src/encoding.h
@@ -27,7 +27,6 @@
 #include <osmocom/gsm/l1sap.h>
 }
 
-struct gprs_rlcmac_bts;
 struct gprs_rlcmac_tbf;
 struct bitvec;
 struct gprs_llc;
@@ -57,7 +56,6 @@
 		);
 
 	static void write_packet_uplink_assignment(
-			struct gprs_rlcmac_bts *bts,
 			bitvec * dest, uint8_t old_tfi,
 			uint8_t old_downlink, uint32_t tlli, uint8_t use_tlli,
 			struct gprs_rlcmac_ul_tbf *tbf, uint8_t poll, uint8_t rrbp,
@@ -76,8 +74,7 @@
 		bitvec * dest, uint32_t tlli);
 
 	static void write_packet_uplink_ack(
-			struct gprs_rlcmac_bts *bts, bitvec * dest,
-			struct gprs_rlcmac_ul_tbf *tbf, bool is_final,
+			bitvec * dest, struct gprs_rlcmac_ul_tbf *tbf, bool is_final,
 			uint8_t rrbp);
 
 	static int write_paging_request(bitvec * dest, uint8_t *ptmsi, uint16_t ptmsi_len);
diff --git a/src/tbf.cpp b/src/tbf.cpp
index dc90dbb..a099322 100644
--- a/src/tbf.cpp
+++ b/src/tbf.cpp
@@ -1365,7 +1365,7 @@
 		return NULL;
 	}
 	bitvec_unhex(ass_vec, DUMMY_VEC);
-	Encoding::write_packet_uplink_assignment(bts_data(), ass_vec, m_tfi,
+	Encoding::write_packet_uplink_assignment(ass_vec, m_tfi,
 		(direction == GPRS_RLCMAC_DL_TBF), tlli(),
 		is_tlli_valid(), new_tbf, 1, rrbp, bts_data()->alpha,
 		bts_data()->gamma, -1, is_egprs_enabled());
diff --git a/src/tbf_ul.cpp b/src/tbf_ul.cpp
index e1a0fbd..55c83e7 100644
--- a/src/tbf_ul.cpp
+++ b/src/tbf_ul.cpp
@@ -153,7 +153,7 @@
 		return NULL;
 	}
 	bitvec_unhex(ack_vec, DUMMY_VEC);
-	Encoding::write_packet_uplink_ack(bts_data(), ack_vec, this, final, rrbp);
+	Encoding::write_packet_uplink_ack(ack_vec, this, final, rrbp);
 	bitvec_pack(ack_vec, msgb_put(msg, 23));
 	bitvec_free(ack_vec);