diff --git a/mini-lsm-mvcc/src/mem_table.rs b/mini-lsm-mvcc/src/mem_table.rs
index 92d90d76..b7e0d77e 100644
--- a/mini-lsm-mvcc/src/mem_table.rs
+++ b/mini-lsm-mvcc/src/mem_table.rs
@@ -93,7 +93,7 @@ impl MemTable {
     /// Get a value by key. Should not be used in week 3.
     pub fn get(&self, key: KeySlice) -> Option<Bytes> {
         let key_bytes = KeyBytes::from_bytes_with_ts(
-            Bytes::from_static(unsafe { std::mem::transmute(key.key_ref()) }),
+            Bytes::from_static(unsafe { std::mem::transmute::<&[u8], &[u8]>(key.key_ref()) }),
             key.ts(),
         );
         self.map.get(&key_bytes).map(|e| e.value().clone())