diff --git a/langchain/src/chains/combine_documents/base.ts b/langchain/src/chains/combine_documents/base.ts
index cf4cb70c833c..5ffa53df6c3d 100644
--- a/langchain/src/chains/combine_documents/base.ts
+++ b/langchain/src/chains/combine_documents/base.ts
@@ -21,6 +21,9 @@ export async function formatDocuments({
   documents: Document[];
   config?: RunnableConfig;
 }) {
+  if (documents == null || documents.length === 0) {
+    return "";
+  }
   const formattedDocs = await Promise.all(
     documents.map((document) =>
       documentPrompt
diff --git a/libs/langchain-cohere/src/rerank.ts b/libs/langchain-cohere/src/rerank.ts
index 78a13efa2f83..0dd5834e2527 100644
--- a/libs/langchain-cohere/src/rerank.ts
+++ b/libs/langchain-cohere/src/rerank.ts
@@ -60,6 +60,9 @@ export class CohereRerank extends BaseDocumentCompressor {
     documents: Array<DocumentInterface>,
     query: string
   ): Promise<Array<DocumentInterface>> {
+    if (documents == null || documents.length === 0) {
+      return [];
+    }
     const _docs = documents.map((doc) => doc.pageContent);
     const { results } = await this.client.rerank({
       model: this.model,