diff --git a/package.json b/package.json
index c244ebb..7e1581e 100644
--- a/package.json
+++ b/package.json
@@ -7,6 +7,7 @@
         "@lumeweb/cfg": "https://github.com/LumeWeb/bcfg.git",
         "@types/node": "^18.7.16",
         "express": "^4.18.1",
-        "loglevel": "^1.8.0"
+        "loglevel": "^1.8.0",
+        "node-cache": "^5.1.2"
     }
 }
diff --git a/src/rpc.ts b/src/rpc.ts
index 4f0b3ae..fd51fc8 100644
--- a/src/rpc.ts
+++ b/src/rpc.ts
@@ -1,4 +1,5 @@
 import type EventEmitter from "events";
+import type NodeCache from "node-cache";
 
 export interface RPCRequest {
   module: string;
@@ -54,7 +55,7 @@ export declare class RPCServer extends EventEmitter {
   public static hashQuery(query: RPCRequest): string;
 }
 export declare class RPCCache extends EventEmitter {
-  get data(): RPCCacheData;
+  get data(): NodeCache;
   constructor(server: RPCServer);
   public signResponse(item: RPCCacheItem): any;
   public verifyResponse(pubkey: Buffer, item: RPCCacheItem): boolean | Buffer;