diff --git a/pvmfw/src/helpers.rs b/pvmfw/src/helpers.rs
index 6310826..9c739d1 100644
--- a/pvmfw/src/helpers.rs
+++ b/pvmfw/src/helpers.rs
@@ -40,18 +40,19 @@
 }
 
 /// Write a value to a system register.
+///
+/// # Safety
+///
+/// Callers must ensure that side effects of updating the system register are properly handled.
 #[macro_export]
 macro_rules! write_sysreg {
     ($sysreg:literal, $val:expr) => {{
         let value: usize = $val;
-        // Safe because it writes a system register and does not affect Rust.
-        unsafe {
-            core::arch::asm!(
-                concat!("msr ", $sysreg, ", {}"),
-                in(reg) value,
-                options(nomem, nostack, preserves_flags),
-            )
-        }
+        core::arch::asm!(
+            concat!("msr ", $sysreg, ", {}"),
+            in(reg) value,
+            options(nomem, nostack, preserves_flags),
+        )
     }};
 }