diff --git a/hw/vendor/patches/pulp_platform_fpnew/0001-fpnew-fix-modelsim-issue-with-reduced-visibility.patch b/hw/vendor/patches/pulp_platform_fpnew/0001-fpnew-fix-modelsim-issue-with-reduced-visibility.patch
new file mode 100644
index 000000000..ae036374c
--- /dev/null
+++ b/hw/vendor/patches/pulp_platform_fpnew/0001-fpnew-fix-modelsim-issue-with-reduced-visibility.patch
@@ -0,0 +1,34 @@
+From 62c12c42d1d9865c21ba5492d51ebd79641a43db Mon Sep 17 00:00:00 2001
+From: Luca Bertaccini <lbertaccini@iis.ee.ethz.ch>
+Date: Thu, 12 May 2022 18:41:10 +0200
+Subject: [PATCH] fpnew fix modelsim issue with reduced visibility
+
+---
+ src/fpnew_opgroup_multifmt_slice.sv | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/src/fpnew_opgroup_multifmt_slice.sv b/src/fpnew_opgroup_multifmt_slice.sv
+index 2f31f50..2245b39 100644
+--- a/src/fpnew_opgroup_multifmt_slice.sv
++++ b/src/fpnew_opgroup_multifmt_slice.sv
+@@ -342,7 +342,7 @@ module fpnew_opgroup_multifmt_slice #(
+       assign lane_out_valid[lane] = out_valid & ((lane == 0) | result_is_vector);
+ 
+       // Properly NaN-box or sign-extend the slice result if not in use
+-      assign local_result      = lane_out_valid[lane] ? op_result : '{default: lane_ext_bit[0]};
++      assign local_result      = lane_out_valid[lane] ? op_result : {(LANE_WIDTH){lane_ext_bit[0]}};
+       assign lane_status[lane] = lane_out_valid[lane] ? op_status : '0;
+ 
+     // Otherwise generate constant sign-extension
+@@ -352,7 +352,7 @@ module fpnew_opgroup_multifmt_slice #(
+       assign lane_aux[lane]       = 1'b0; // unused lane
+       assign lane_tags[lane]      = 1'b0; // unused lane
+       assign lane_ext_bit[lane]   = 1'b1; // NaN-box unused lane
+-      assign local_result         = '{default: lane_ext_bit[0]}; // sign-extend/nan box
++      assign local_result         = {(LANE_WIDTH){lane_ext_bit[0]}}; // sign-extend/nan box
+       assign lane_status[lane]    = '0;
+       assign lane_busy[lane]      = 1'b0;
+     end
+-- 
+2.16.5
+
diff --git a/hw/vendor/pulp_platform_fpnew.vendor.hjson b/hw/vendor/pulp_platform_fpnew.vendor.hjson
index 69100945f..eab14f0a3 100644
--- a/hw/vendor/pulp_platform_fpnew.vendor.hjson
+++ b/hw/vendor/pulp_platform_fpnew.vendor.hjson
@@ -10,6 +10,8 @@
     rev: "feature/expanding_dotp",
   },
 
+  patch_dir: "patches/pulp_platform_fpnew",
+
   exclude_from_upstream: [
     "src/common_cells",
     "src/fpu_div_sqrt_mvp",
diff --git a/hw/vendor/pulp_platform_fpnew/src/fpnew_opgroup_multifmt_slice.sv b/hw/vendor/pulp_platform_fpnew/src/fpnew_opgroup_multifmt_slice.sv
index 2f31f5009..2245b3993 100644
--- a/hw/vendor/pulp_platform_fpnew/src/fpnew_opgroup_multifmt_slice.sv
+++ b/hw/vendor/pulp_platform_fpnew/src/fpnew_opgroup_multifmt_slice.sv
@@ -342,7 +342,7 @@ module fpnew_opgroup_multifmt_slice #(
       assign lane_out_valid[lane] = out_valid & ((lane == 0) | result_is_vector);
 
       // Properly NaN-box or sign-extend the slice result if not in use
-      assign local_result      = lane_out_valid[lane] ? op_result : '{default: lane_ext_bit[0]};
+      assign local_result      = lane_out_valid[lane] ? op_result : {(LANE_WIDTH){lane_ext_bit[0]}};
       assign lane_status[lane] = lane_out_valid[lane] ? op_status : '0;
 
     // Otherwise generate constant sign-extension
@@ -352,7 +352,7 @@ module fpnew_opgroup_multifmt_slice #(
       assign lane_aux[lane]       = 1'b0; // unused lane
       assign lane_tags[lane]      = 1'b0; // unused lane
       assign lane_ext_bit[lane]   = 1'b1; // NaN-box unused lane
-      assign local_result         = '{default: lane_ext_bit[0]}; // sign-extend/nan box
+      assign local_result         = {(LANE_WIDTH){lane_ext_bit[0]}}; // sign-extend/nan box
       assign lane_status[lane]    = '0;
       assign lane_busy[lane]      = 1'b0;
     end