diff --git a/packages/core/src/cloud/LlamaCloudIndex.ts b/packages/core/src/cloud/LlamaCloudIndex.ts
index 058be7ccdd593335170ab0967d75d099b7ac39ba..0daa76c8d19d268ef42c662f7577dbca8d66cf03 100644
--- a/packages/core/src/cloud/LlamaCloudIndex.ts
+++ b/packages/core/src/cloud/LlamaCloudIndex.ts
@@ -13,7 +13,7 @@ export class LlamaCloudIndex {
     this.params = params;
   }
 
-  asRetriever(params: RetrieveParams): BaseRetriever {
+  asRetriever(params: RetrieveParams = {}): BaseRetriever {
     return new LlamaCloudRetriever({ ...this.params, ...params });
   }
 
diff --git a/packages/core/src/cloud/LlamaCloudRetriever.ts b/packages/core/src/cloud/LlamaCloudRetriever.ts
index 43616b80c438f0833b7d5299a439ca7981ea18ea..9773831342a4416f68657636c14084d1f06cf33a 100644
--- a/packages/core/src/cloud/LlamaCloudRetriever.ts
+++ b/packages/core/src/cloud/LlamaCloudRetriever.ts
@@ -38,8 +38,9 @@ export class LlamaCloudRetriever implements BaseRetriever {
 
   constructor(params: CloudConstructorParams & RetrieveParams) {
     this.clientParams = { apiKey: params.apiKey, baseUrl: params.baseUrl };
-    params.denseSimilarityTopK =
-      params.similarityTopK ?? params.denseSimilarityTopK;
+    if (params.similarityTopK) {
+      params.denseSimilarityTopK = params.similarityTopK;
+    }
     this.retrieveParams = params;
     this.pipelineName = params.name;
     if (params.projectName) {