diff --git a/hw/vendor/patches/pulp_axi/0008_Keep_unstrobed_mailbox_threshold_bytes.patch b/hw/vendor/patches/pulp_axi/0008_Keep_unstrobed_mailbox_threshold_bytes.patch
new file mode 100644
index 000000000..f385f65e0
--- /dev/null
+++ b/hw/vendor/patches/pulp_axi/0008_Keep_unstrobed_mailbox_threshold_bytes.patch
@@ -0,0 +1,32 @@
+From 1160319407d0d5bdc490b6c3ecc0973055b488cd Mon Sep 17 00:00:00 2001
+From: Adam Taback <ataback@tenstorrent.com>
+Date: Wed, 11 Feb 2026 11:25:56 -0500
+Subject: [PATCH] Fixed axi_lite_mailbox wstrb axi violation
+
+Backport of pulp-platform/axi@11603194 (pulp-platform/axi#412, in v0.39.10).
+---
+ src/axi_lite_mailbox.sv | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/axi_lite_mailbox.sv b/src/axi_lite_mailbox.sv
+index 73adeca..8c410d8 100644
+--- a/src/axi_lite_mailbox.sv
++++ b/src/axi_lite_mailbox.sv
+@@ -443,7 +443,7 @@ module axi_lite_mailbox_slave #(
+             // ERROR:  read only
+             WIRQT:  begin
+               for (int unsigned i = 0; i < AxiDataWidth/8; i++) begin
+-                wirqt_d[i*8+:8] = slv_req_i.w.strb[i] ? slv_req_i.w.data[i*8+:8] : 8'b0000_0000;
++                wirqt_d[i*8+:8] = slv_req_i.w.strb[i] ? slv_req_i.w.data[i*8+:8] : wirqt_d[i*8+:8];
+               end
+               if (wirqt_d >= data_t'(MailboxDepth)) begin
+                 // the `-1` is to have the interrupt fireing when the FIFO is comletely full
+@@ -454,7 +454,7 @@ module axi_lite_mailbox_slave #(
+             end
+             RIRQT:  begin
+               for (int unsigned i = 0; i < AxiDataWidth/8; i++) begin
+-                rirqt_d[i*8+:8] = slv_req_i.w.strb[i] ? slv_req_i.w.data[i*8+:8] : 8'b0000_0000;
++                rirqt_d[i*8+:8] = slv_req_i.w.strb[i] ? slv_req_i.w.data[i*8+:8] : rirqt_d[i*8+:8];
+               end
+               if (rirqt_d >= data_t'(MailboxDepth)) begin
+               // Threshold to maximal value, minus two to prevent overflow in usage
diff --git a/hw/vendor/pulp_axi/src/axi_lite_mailbox.sv b/hw/vendor/pulp_axi/src/axi_lite_mailbox.sv
index 73adeca38..8c410d83d 100644
--- a/hw/vendor/pulp_axi/src/axi_lite_mailbox.sv
+++ b/hw/vendor/pulp_axi/src/axi_lite_mailbox.sv
@@ -443,7 +443,7 @@ module axi_lite_mailbox_slave #(
             // ERROR:  read only
             WIRQT:  begin
               for (int unsigned i = 0; i < AxiDataWidth/8; i++) begin
-                wirqt_d[i*8+:8] = slv_req_i.w.strb[i] ? slv_req_i.w.data[i*8+:8] : 8'b0000_0000;
+                wirqt_d[i*8+:8] = slv_req_i.w.strb[i] ? slv_req_i.w.data[i*8+:8] : wirqt_d[i*8+:8];
               end
               if (wirqt_d >= data_t'(MailboxDepth)) begin
                 // the `-1` is to have the interrupt fireing when the FIFO is comletely full
@@ -454,7 +454,7 @@ module axi_lite_mailbox_slave #(
             end
             RIRQT:  begin
               for (int unsigned i = 0; i < AxiDataWidth/8; i++) begin
-                rirqt_d[i*8+:8] = slv_req_i.w.strb[i] ? slv_req_i.w.data[i*8+:8] : 8'b0000_0000;
+                rirqt_d[i*8+:8] = slv_req_i.w.strb[i] ? slv_req_i.w.data[i*8+:8] : rirqt_d[i*8+:8];
               end
               if (rirqt_d >= data_t'(MailboxDepth)) begin
               // Threshold to maximal value, minus two to prevent overflow in usage