diff --git a/src/agentlab/llm/huggingface_utils.py b/src/agentlab/llm/huggingface_utils.py
index 470324bd..153978b1 100644
--- a/src/agentlab/llm/huggingface_utils.py
+++ b/src/agentlab/llm/huggingface_utils.py
@@ -6,6 +6,7 @@
 from transformers import AutoTokenizer, GPT2TokenizerFast
 
 from agentlab.llm.base_api import AbstractChatModel
+from agentlab.llm.llm_utils import Discussion
 from agentlab.llm.prompt_templates import PromptTemplate, get_prompt_template
 
 
@@ -59,6 +60,8 @@ def __call__(
         if self.tokenizer:
             # messages_formated = _convert_messages_to_dict(messages) ## ?
             try:
+                if isinstance(messages, Discussion):
+                    messages.merge()
                 prompt = self.tokenizer.apply_chat_template(messages, tokenize=False)
             except Exception as e:
                 if "Conversation roles must alternate" in str(e):
diff --git a/src/agentlab/llm/llm_utils.py b/src/agentlab/llm/llm_utils.py
index 43d9dd5b..e3300f96 100644
--- a/src/agentlab/llm/llm_utils.py
+++ b/src/agentlab/llm/llm_utils.py
@@ -386,6 +386,8 @@ def merge(self):
             else:
                 new_content.append(elem)
         self["content"] = new_content
+        if len(self["content"]) == 1:
+            self["content"] = self["content"][0]["text"]
 
 
 class SystemMessage(BaseMessage):
diff --git a/tests/llm/test_llm_utils.py b/tests/llm/test_llm_utils.py
index 5597760a..d7c42853 100644
--- a/tests/llm/test_llm_utils.py
+++ b/tests/llm/test_llm_utils.py
@@ -251,8 +251,7 @@ def test_message_merge_only_text():
     ]
     message = llm_utils.BaseMessage(role="system", content=content)
     message.merge()
-    assert len(message["content"]) == 1
-    assert message["content"][0]["text"] == "Hello, world!\nThis is a test."
+    assert message["content"] == "Hello, world!\nThis is a test."
 
 
 def test_message_merge_text_image():