diff --git a/langchain/experimental/autonomous_agents/autogpt/prompt.py b/langchain/experimental/autonomous_agents/autogpt/prompt.py
index 909e9b0c4b9..d1f3a9b74af 100644
--- a/langchain/experimental/autonomous_agents/autogpt/prompt.py
+++ b/langchain/experimental/autonomous_agents/autogpt/prompt.py
@@ -70,6 +70,7 @@ class AutoGPTPrompt(BaseChatPromptTemplate, BaseModel):
             if used_tokens + message_tokens > self.send_token_limit - 1000:
                 break
             historical_messages = [message] + historical_messages
+            used_tokens += message_tokens
         input_message = HumanMessage(content=kwargs["user_input"])
         messages: List[BaseMessage] = [base_prompt, time_prompt, memory_message]
         messages += historical_messages