diff --git a/src/zircon/rtl/zircon_ip_len_cksum.sv b/src/zircon/rtl/zircon_ip_len_cksum.sv
index f0b641d..afd27b4 100644
--- a/src/zircon/rtl/zircon_ip_len_cksum.sv
+++ b/src/zircon/rtl/zircon_ip_len_cksum.sv
@@ -84,27 +84,11 @@ logic [ID_W-1:0] m_axis_meta_id_reg = '0;
 logic [DEST_W-1:0] m_axis_meta_dest_reg = '0;
 logic [USER_W-1:0] m_axis_meta_user_reg = '0;
 
-assign m_axis_pkt.tdata = s_axis_pkt.tdata;
-assign m_axis_pkt.tkeep = s_axis_pkt.tkeep;
-assign m_axis_pkt.tstrb = s_axis_pkt.tstrb;
-if (ID_EN) begin
-    assign m_axis_pkt.tid = s_axis_pkt.tid;
-end else begin
-    assign m_axis_pkt.tid = '0;
-end
-if (DEST_EN) begin
-    assign m_axis_pkt.tdest = s_axis_pkt.tdest;
-end else begin
-    assign m_axis_pkt.tdest = '0;
-end
-if (USER_EN) begin
-    assign m_axis_pkt.tuser = s_axis_pkt.tuser;
-end else begin
-    assign m_axis_pkt.tuser = '0;
-end
-assign m_axis_pkt.tlast = s_axis_pkt.tlast;
-assign m_axis_pkt.tvalid = s_axis_pkt.tvalid;
-assign s_axis_pkt.tready = m_axis_pkt.tready;
+taxi_axis_tie
+axis_tie_pkt_inst (
+    .s_axis(s_axis_pkt),
+    .m_axis(m_axis_pkt)
+);
 
 assign m_axis_meta.tdata = {m_axis_meta_csum_reg, m_axis_meta_len_reg};
 assign m_axis_meta.tkeep = '1;
diff --git a/src/zircon/rtl/zircon_ip_tx_egress.sv b/src/zircon/rtl/zircon_ip_tx_egress.sv
index 381be62..341cb08 100644
--- a/src/zircon/rtl/zircon_ip_tx_egress.sv
+++ b/src/zircon/rtl/zircon_ip_tx_egress.sv
@@ -85,16 +85,11 @@ hdr_adapter_inst (
     .m_axis(pkt_parts[0])
 );
 
-assign pkt_parts[1].tdata = s_axis_pkt.tdata;
-assign pkt_parts[1].tkeep = s_axis_pkt.tkeep;
-assign pkt_parts[1].tstrb = s_axis_pkt.tstrb;
-assign pkt_parts[1].tvalid = s_axis_pkt.tvalid;
-assign pkt_parts[1].tlast = s_axis_pkt.tlast;
-assign pkt_parts[1].tid = s_axis_pkt.tid;
-assign pkt_parts[1].tdest = s_axis_pkt.tdest;
-assign pkt_parts[1].tuser = s_axis_pkt.tuser;
-
-assign s_axis_pkt.tready = pkt_parts[1].tready;
+taxi_axis_tie
+axis_tie_pkt_inst (
+    .s_axis(s_axis_pkt),
+    .m_axis(pkt_parts[1])
+);
 
 // combine header and payload
 taxi_axis_concat #(
diff --git a/src/zircon/tb/zircon_ip_len_cksum/Makefile b/src/zircon/tb/zircon_ip_len_cksum/Makefile
index 84c1326..37b743b 100644
--- a/src/zircon/tb/zircon_ip_len_cksum/Makefile
+++ b/src/zircon/tb/zircon_ip_len_cksum/Makefile
@@ -24,6 +24,7 @@ MODULE   = $(COCOTB_TEST_MODULES)
 TOPLEVEL = $(COCOTB_TOPLEVEL)
 VERILOG_SOURCES += $(COCOTB_TOPLEVEL).sv
 VERILOG_SOURCES += $(RTL_DIR)/$(DUT).sv
+VERILOG_SOURCES += $(TAXI_SRC_DIR)/axis/rtl/taxi_axis_tie.sv
 VERILOG_SOURCES += $(TAXI_SRC_DIR)/axis/rtl/taxi_axis_if.sv
 
 # handle file list files
diff --git a/src/zircon/tb/zircon_ip_len_cksum/test_zircon_ip_len_cksum.py b/src/zircon/tb/zircon_ip_len_cksum/test_zircon_ip_len_cksum.py
index bc7cf70..961016c 100644
--- a/src/zircon/tb/zircon_ip_len_cksum/test_zircon_ip_len_cksum.py
+++ b/src/zircon/tb/zircon_ip_len_cksum/test_zircon_ip_len_cksum.py
@@ -259,6 +259,7 @@ def test_zircon_ip_len_cksum(request, data_w=32):
     verilog_sources = [
         os.path.join(tests_dir, f"{toplevel}.sv"),
         os.path.join(rtl_dir, f"{dut}.sv"),
+        os.path.join(taxi_src_dir, "axis", "rtl", "taxi_axis_tie.sv"),
         os.path.join(taxi_src_dir, "axis", "rtl", "taxi_axis_if.sv"),
     ]