diff --git a/src/gprs_rlcmac.cpp b/src/gprs_rlcmac.cpp
index 419470b..7ab187f 100644
--- a/src/gprs_rlcmac.cpp
+++ b/src/gprs_rlcmac.cpp
@@ -587,13 +587,14 @@
 }
 
 /* generate uplink assignment */
-void write_packet_uplink_assignment(bitvec * dest, uint8_t old_tfi,
+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_tbf *tbf, uint8_t poll, uint8_t alpha,
 	uint8_t gamma, int8_t ta_idx)
 {
 	// TODO We should use our implementation of encode RLC/MAC Control messages.
-	struct gprs_rlcmac_bts *bts = gprs_rlcmac_bts;
 	unsigned wp = 0;
 	uint8_t ts;