diff --git a/libraries/persistent_store/src/buffer.rs b/libraries/persistent_store/src/buffer.rs
index 076ba0d..a511141 100644
--- a/libraries/persistent_store/src/buffer.rs
+++ b/libraries/persistent_store/src/buffer.rs
@@ -310,7 +310,9 @@ impl Storage for BufferStorage {
         // Check and update counters.
         self.incr_page_erases(page);
         // Write to the storage.
-        self.storage[range].fill(0xff);
+        for byte in &mut self.storage[range] {
+            *byte = 0xff;
+        }
         Ok(())
     }
 }
diff --git a/libraries/persistent_store/src/lib.rs b/libraries/persistent_store/src/lib.rs
index 942192f..fd85711 100644
--- a/libraries/persistent_store/src/lib.rs
+++ b/libraries/persistent_store/src/lib.rs
@@ -13,7 +13,6 @@
 // limitations under the License.
 
 #![cfg_attr(not(feature = "std"), no_std)]
-#![feature(slice_fill)]
 
 extern crate alloc;