diff --git a/libs/langchain-anthropic/src/chat_models.ts b/libs/langchain-anthropic/src/chat_models.ts
index 83e24b8f6897..74fb4e359568 100644
--- a/libs/langchain-anthropic/src/chat_models.ts
+++ b/libs/langchain-anthropic/src/chat_models.ts
@@ -606,10 +606,10 @@ export class ChatAnthropicMessages<
   clientOptions: ClientOptions;
 
   // Used for non-streaming requests
-  protected batchClient!: Anthropic;
+  protected batchClient: Anthropic;
 
   // Used for streaming requests
-  protected streamingClient!: Anthropic;
+  protected streamingClient: Anthropic;
 
   streamUsage = true;