diff --git a/talk.py b/talk.py
index 8053c75..00530b2 100644
--- a/talk.py
+++ b/talk.py
@@ -47,7 +47,7 @@ class Talk:
     @classmethod
     def __get_message (
             cls,
-            message:        str,
+            message:        str | list,
             name:           str | None,
             histories:      list,
             goatoh_mode:    bool        = False,
@@ -234,10 +234,17 @@ class Talk:
 
         messages += histories + [{'role': 'user', 'content': message}]
 
+        # デバッグ用
+        print (messages)
+
         try:
-            return openai.chat.completions.create (
-                    model = 'gpt-4o' if random.random () < .2 else 'gpt-3.5-turbo',
-                    messages = messages).choices[0].message
+            return (openai.chat.completions.create (
+                        model    = ('gpt-4o'
+                                    if any (type (e['content']) is list
+                                            for e in messages)
+                                    else 'gpt-3.5-turbo'),
+                        messages = messages)
+                    .choices[0].message)
         except:
             return None