diff --git a/lib/tdf3/src/client/index.ts b/lib/tdf3/src/client/index.ts
index 1d597f1b..5d0b7fe1 100644
--- a/lib/tdf3/src/client/index.ts
+++ b/lib/tdf3/src/client/index.ts
@@ -222,7 +222,7 @@ export class Client {
    */
   readonly allowedKases: string[];
 
-  readonly kasKeys: Record<string, Promise<KasPublicKeyInfo>>;
+  readonly kasKeys: Record<string, Promise<KasPublicKeyInfo>> = {};
 
   readonly easEndpoint?: string;