diff --git a/Sources/Bodega/Documentation.docc/Articles/Fundamentals/Using StorageEngines.md b/Sources/Bodega/Documentation.docc/Articles/Fundamentals/Using StorageEngines.md
index 01bc0dd..a4792e7 100644
--- a/Sources/Bodega/Documentation.docc/Articles/Fundamentals/Using StorageEngines.md	
+++ b/Sources/Bodega/Documentation.docc/Articles/Fundamentals/Using StorageEngines.md	
@@ -28,6 +28,7 @@ public protocol StorageEngine: Actor {
     func removeAllData() async throws
 
     func keyExists(_ key: CacheKey) async -> Bool
+    func keysExist(_ keys: [CacheKey]) async -> [CacheKey]
     func keyCount() async -> Int
     func allKeys() async -> [CacheKey]
 
diff --git a/Sources/Bodega/StorageEngine.swift b/Sources/Bodega/StorageEngine.swift
index 6dfa391..42f2b94 100644
--- a/Sources/Bodega/StorageEngine.swift
+++ b/Sources/Bodega/StorageEngine.swift
@@ -94,7 +94,7 @@ extension StorageEngine {
     public func keysExist(_ keys: [CacheKey]) async -> [CacheKey] {
         let allKeys = await self.allKeys()
         let keySet = Set(allKeys)
-        return keys.filter { keySet.contains($0) }
+        return keys.filter({ keySet.contains($0) })
     }
     
     /// Read the number of keys located in the ``StorageEngine``.