diff --git a/src/CP0/CP0.sv b/src/CP0/CP0.sv
index 02a5ad8..f471e17 100644
--- a/src/CP0/CP0.sv
+++ b/src/CP0/CP0.sv
@@ -58,7 +58,8 @@ module CP0 (
   assign rf_cp0.Cause.zero3    = 2'b00;
   assign rf_cp0.Status.zero1   = 9'b0;
   assign rf_cp0.Status.zero2   = 6'b0;
-  assign rf_cp0.Status.zero3   = 6'b0;
+  assign rf_cp0.Status.zero3   = 3'b0;
+  assign rf_cp0.Status.zero4   = 2'b0;
   assign rf_cp0.EntryHi.zero   = 5'b0;
   assign rf_cp0.Wired.zero     = 29'b0;
   assign rf_cp0.EntryLo1.zero  = 6'b0;
@@ -97,6 +98,7 @@ module CP0 (
       rf_cp0.Cause.ExcCode = 5'b0;
       rf_cp0.Status.Bev    = 1'b1;
       rf_cp0.Status.IM     = 8'b0;
+      rf_cp0.Status.UM     = 1'b0;
       rf_cp0.Status.EXL    = 1'b0;
       rf_cp0.Status.IE     = 1'b0;
       rf_cp0.Compare       = 32'hFFFF_FFFF;
@@ -156,6 +158,7 @@ module CP0 (
           12: begin
             rf_cp0.Status.Bev = wdata[22];
             rf_cp0.Status.IM  = wdata[15:8];
+            rf_cp0.Status.UM  = wdata[4];
             rf_cp0.Status.EXL = wdata[1];
             rf_cp0.Status.IE  = wdata[0];
           end
diff --git a/src/include/CP0.svh b/src/include/CP0.svh
index 89b8c2c..b5c7e9e 100644
--- a/src/include/CP0.svh
+++ b/src/include/CP0.svh
@@ -65,7 +65,9 @@ typedef struct packed {
   logic       Bev;
   logic [5:0] zero2;
   logic [7:0] IM;
-  logic [5:0] zero3;
+  logic [2:0] zero3;
+  logic       UM;
+  logic [1:0] zero4;
   logic       EXL;
   logic       IE;
 } CP0_REGS_STATUS_t;