diff --git a/rtl/arp_eth_rx.v b/rtl/arp_eth_rx.v
index 75961cbe4..2223b40a5 100644
--- a/rtl/arp_eth_rx.v
+++ b/rtl/arp_eth_rx.v
@@ -181,7 +181,7 @@ assign error_header_early_termination = error_header_early_termination_reg;
 assign error_invalid_header = error_invalid_header_reg;
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_eth_hdr_ready_next = 0;
     input_eth_payload_tready_next = 0;
diff --git a/rtl/arp_eth_rx_64.v b/rtl/arp_eth_rx_64.v
index 7a56c52c9..d02163408 100644
--- a/rtl/arp_eth_rx_64.v
+++ b/rtl/arp_eth_rx_64.v
@@ -158,7 +158,7 @@ assign error_header_early_termination = error_header_early_termination_reg;
 assign error_invalid_header = error_invalid_header_reg;
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_eth_hdr_ready_next = 0;
     input_eth_payload_tready_next = 0;
diff --git a/rtl/arp_eth_tx.v b/rtl/arp_eth_tx.v
index f12475bc1..30d620a55 100644
--- a/rtl/arp_eth_tx.v
+++ b/rtl/arp_eth_tx.v
@@ -139,7 +139,7 @@ assign output_eth_type = output_eth_type_reg;
 assign busy = busy_reg;
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_frame_ready_next = 0;
 
diff --git a/rtl/arp_eth_tx_64.v b/rtl/arp_eth_tx_64.v
index 5b49ea1e9..4a6a2d913 100644
--- a/rtl/arp_eth_tx_64.v
+++ b/rtl/arp_eth_tx_64.v
@@ -141,7 +141,7 @@ assign output_eth_type = output_eth_type_reg;
 assign busy = busy_reg;
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_frame_ready_next = 0;
 
diff --git a/rtl/eth_axis_rx.v b/rtl/eth_axis_rx.v
index 5a795e141..a962b42a4 100644
--- a/rtl/eth_axis_rx.v
+++ b/rtl/eth_axis_rx.v
@@ -133,7 +133,7 @@ assign busy = busy_reg;
 assign error_header_early_termination = error_header_early_termination_reg;
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_axis_tready_next = 0;
 
diff --git a/rtl/eth_axis_rx_64.v b/rtl/eth_axis_rx_64.v
index 3fb2d3b66..230bd2b28 100644
--- a/rtl/eth_axis_rx_64.v
+++ b/rtl/eth_axis_rx_64.v
@@ -162,7 +162,7 @@ always @* begin
 end
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_axis_tready_next = 0;
 
diff --git a/rtl/eth_axis_tx.v b/rtl/eth_axis_tx.v
index c420d2029..f62c07939 100644
--- a/rtl/eth_axis_tx.v
+++ b/rtl/eth_axis_tx.v
@@ -113,7 +113,7 @@ assign input_eth_payload_tready = input_eth_payload_tready_reg;
 assign busy = busy_reg;
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_eth_hdr_ready_next = 0;
     input_eth_payload_tready_next = 0;
diff --git a/rtl/eth_axis_tx_64.v b/rtl/eth_axis_tx_64.v
index 5b351f027..32906e230 100644
--- a/rtl/eth_axis_tx_64.v
+++ b/rtl/eth_axis_tx_64.v
@@ -155,7 +155,7 @@ always @* begin
 end
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_eth_hdr_ready_next = 0;
     input_eth_payload_tready_next = 0;
diff --git a/rtl/ip.v b/rtl/ip.v
index 67328486d..d0a0d8236 100644
--- a/rtl/ip.v
+++ b/rtl/ip.v
@@ -253,7 +253,7 @@ assign arp_request_ip = input_ip_dest_ip;
 assign tx_error_arp_failed = arp_response_error;
 
 always @* begin
-    state_next = 8'bz;
+    state_next = STATE_IDLE;
 
     arp_request_valid_next = 0;
     drop_packet_next = 0;
diff --git a/rtl/ip_64.v b/rtl/ip_64.v
index b7ed26b80..126b0e9d3 100644
--- a/rtl/ip_64.v
+++ b/rtl/ip_64.v
@@ -262,7 +262,7 @@ assign arp_request_ip = input_ip_dest_ip;
 assign tx_error_arp_failed = arp_response_error;
 
 always @* begin
-    state_next = 8'bz;
+    state_next = STATE_IDLE;
 
     arp_request_valid_next = 0;
     drop_packet_next = 0;
diff --git a/rtl/ip_eth_rx.v b/rtl/ip_eth_rx.v
index 0d95789f9..237202ce6 100644
--- a/rtl/ip_eth_rx.v
+++ b/rtl/ip_eth_rx.v
@@ -227,7 +227,7 @@ function [15:0] add1c16b;
 endfunction
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_eth_hdr_ready_next = 0;
     input_eth_payload_tready_next = 0;
diff --git a/rtl/ip_eth_rx_64.v b/rtl/ip_eth_rx_64.v
index ca2cfaa10..e0e4b9cb2 100644
--- a/rtl/ip_eth_rx_64.v
+++ b/rtl/ip_eth_rx_64.v
@@ -276,7 +276,7 @@ always @* begin
 end
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     flush_save = 0;
     transfer_in_save = 0;
diff --git a/rtl/ip_eth_tx.v b/rtl/ip_eth_tx.v
index 73bf5ca59..0bbe2d314 100644
--- a/rtl/ip_eth_tx.v
+++ b/rtl/ip_eth_tx.v
@@ -180,7 +180,7 @@ function [15:0] add1c16b;
 endfunction
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_ip_hdr_ready_next = 0;
     input_ip_payload_tready_next = 0;
diff --git a/rtl/ip_eth_tx_64.v b/rtl/ip_eth_tx_64.v
index 2d72eb599..9f6e0c803 100644
--- a/rtl/ip_eth_tx_64.v
+++ b/rtl/ip_eth_tx_64.v
@@ -245,7 +245,7 @@ always @* begin
 end
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_ip_hdr_ready_next = 0;
     input_ip_payload_tready_next = 0;
diff --git a/rtl/udp_ip_rx.v b/rtl/udp_ip_rx.v
index b03b05ed6..99bd176e9 100644
--- a/rtl/udp_ip_rx.v
+++ b/rtl/udp_ip_rx.v
@@ -229,7 +229,7 @@ assign error_header_early_termination = error_header_early_termination_reg;
 assign error_payload_early_termination = error_payload_early_termination_reg;
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_ip_hdr_ready_next = 0;
     input_ip_payload_tready_next = 0;
diff --git a/rtl/udp_ip_rx_64.v b/rtl/udp_ip_rx_64.v
index 63dda8413..b0671a635 100644
--- a/rtl/udp_ip_rx_64.v
+++ b/rtl/udp_ip_rx_64.v
@@ -256,7 +256,7 @@ function [7:0] count2keep;
 endfunction
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_ip_hdr_ready_next = 0;
     input_ip_payload_tready_next = 0;
diff --git a/rtl/udp_ip_tx.v b/rtl/udp_ip_tx.v
index 059227f3f..d2c83cb01 100644
--- a/rtl/udp_ip_tx.v
+++ b/rtl/udp_ip_tx.v
@@ -213,7 +213,7 @@ assign busy = busy_reg;
 assign error_payload_early_termination = error_payload_early_termination_reg;
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_udp_hdr_ready_next = 0;
     input_udp_payload_tready_next = 0;
diff --git a/rtl/udp_ip_tx_64.v b/rtl/udp_ip_tx_64.v
index 0dc083dab..ef660eebe 100644
--- a/rtl/udp_ip_tx_64.v
+++ b/rtl/udp_ip_tx_64.v
@@ -247,7 +247,7 @@ function [7:0] count2keep;
 endfunction
 
 always @* begin
-    state_next = 2'bz;
+    state_next = STATE_IDLE;
 
     input_udp_hdr_ready_next = 0;
     input_udp_payload_tready_next = 0;