diff --git a/incl/iss/arch/riscv_hart_m_p.h b/incl/iss/arch/riscv_hart_m_p.h
index e834dd6..7d11c71 100644
--- a/incl/iss/arch/riscv_hart_m_p.h
+++ b/incl/iss/arch/riscv_hart_m_p.h
@@ -302,7 +302,7 @@ public:
 
         void write_mstatus(T val) {
             auto mask = get_mask();
-            auto new_val = (mstatus.storage.val & ~mask) | (val & mask);
+            auto new_val = (mstatus.backing.val & ~mask) | (val & mask);
             mstatus = new_val;
         }