diff --git a/src/cache.ts b/src/cache.ts
index cb995fe..6109ff8 100644
--- a/src/cache.ts
+++ b/src/cache.ts
@@ -45,7 +45,7 @@ metrics.push(
 
 export class Cache<const KT extends string> {
   private inflights = new Map<string, Promise<unknown>>();
-  private formatKey: (params: KeyParams<KT>) => string;
+  formatKey: (params: KeyParams<KT>) => string;
 
   constructor(
     private keyTemplate: KT,
diff --git a/src/lru.ts b/src/lru.ts
index 938dc58..da1dde4 100644
--- a/src/lru.ts
+++ b/src/lru.ts
@@ -77,4 +77,11 @@ export class LruMemoryCacheStore<T> implements CacheStore<T> {
 
     return Promise.resolve();
   }
+
+  replace(key: string, record: StoreEntity<T>): Promise<void> {
+    if (this.cache.has(key)) {
+      return this.set(key, record);
+    }
+    return Promise.resolve();
+  }
 }