diff --git a/src/blockdevice.rs b/src/blockdevice.rs
index e0f3832..674ae55 100644
--- a/src/blockdevice.rs
+++ b/src/blockdevice.rs
@@ -152,9 +152,7 @@ where
     /// Access a blank sector
     pub fn blank_mut(&mut self, block_idx: BlockIdx) -> &mut Block {
         self.block_idx = Some(block_idx);
-        for b in self.block[0].iter_mut() {
-            *b = 0;
-        }
+        self.block[0].fill(0);
         &mut self.block[0]
     }
 
diff --git a/src/fat/volume.rs b/src/fat/volume.rs
index f160fba..25f67de 100644
--- a/src/fat/volume.rs
+++ b/src/fat/volume.rs
@@ -1158,15 +1158,12 @@ impl FatVolume {
             *number_free_cluster -= 1;
         };
         if zero {
-            let blocks = [Block::new()];
             let start_block_idx = self.cluster_to_block(new_cluster);
             let num_blocks = BlockCount(u32::from(self.blocks_per_cluster));
             for block_idx in start_block_idx.range(num_blocks) {
-                trace!("Zeroing cluster");
-                block_cache
-                    .block_device()
-                    .write(&blocks, block_idx)
-                    .map_err(Error::DeviceError)?;
+                trace!("Zeroing cluster {:?}", block_idx);
+                let _block = block_cache.blank_mut(block_idx);
+                block_cache.write_back()?;
             }
         }
         debug!("All done, returning {:?}", new_cluster);
diff --git a/src/sdcard/mod.rs b/src/sdcard/mod.rs
index 5c3c038..553791f 100644
--- a/src/sdcard/mod.rs
+++ b/src/sdcard/mod.rs
@@ -341,9 +341,7 @@ where
             return Err(Error::ReadError);
         }
 
-        for b in buffer.iter_mut() {
-            *b = 0xFF;
-        }
+        buffer.fill(0xFF);
         self.transfer_bytes(buffer)?;
 
         // These two bytes are always sent. They are either a valid CRC, or