diff --git a/samples/rust/rust_debugfs_scoped.rs b/samples/rust/rust_debugfs_scoped.rs
index 6a575a15a2c2..ca2b154be384 100644
--- a/samples/rust/rust_debugfs_scoped.rs
+++ b/samples/rust/rust_debugfs_scoped.rs
@@ -75,7 +75,10 @@ fn create_file_write(
             GFP_KERNEL,
         )?;
     }
-    let blob = KBox::pin_init(new_mutex!([0x42; SZ_4K]), GFP_KERNEL)?;
+    let blob = KBox::pin_init(
+        new_mutex!(pin_init::init_array_from_fn(|_| 0x42)),
+        GFP_KERNEL,
+    )?;
 
     let scope = KBox::pin_init(
         mod_data.device_dir.scope(