diff --git a/src/chatgpt.ts b/src/chatgpt.ts
index 3c84a86..a193f4d 100644
--- a/src/chatgpt.ts
+++ b/src/chatgpt.ts
@@ -219,7 +219,6 @@ class Chat {
       model: this.model,
       messages,
       stream,
-      logprobs,
       presence_penalty: this.presence_penalty,
       frequency_penalty: this.frequency_penalty,
     };
@@ -237,6 +236,9 @@ class Chat {
         type: "json_object",
       };
     }
+    if (logprobs) {
+      body["logprobs"] = true;
+    }
 
     // parse toolsString to function call format
     const ts = this.toolsString.trim();