diff --git a/pvmfw/src/fdt.rs b/pvmfw/src/fdt.rs
index 2cd1061..0ead435 100644
--- a/pvmfw/src/fdt.rs
+++ b/pvmfw/src/fdt.rs
@@ -827,7 +827,7 @@
     bcc: &[u8],
     new_instance: bool,
     strict_boot: bool,
-    debug_policy: Option<&mut [u8]>,
+    debug_policy: Option<&[u8]>,
     debuggable: bool,
     kaslr_seed: u64,
 ) -> libfdt::Result<()> {