diff --git a/vllm/tokenizers/deepseek_v32_encoding.py b/vllm/tokenizers/deepseek_v32_encoding.py
index fb8989e651e3a..521bd92959312 100644
--- a/vllm/tokenizers/deepseek_v32_encoding.py
+++ b/vllm/tokenizers/deepseek_v32_encoding.py
@@ -95,8 +95,10 @@ def tool_calls_to_openai_format(tool_calls):
 def encode_arguments_to_dsml(tool_call: dict[str, str]) -> str:
     p_dsml_template = """<{dsml_token}parameter name="{key}" string="{is_str}">{value}</{dsml_token}parameter>"""
     P_dsml_strs = []
-
-    arguments = json.loads(tool_call["arguments"])
+    if isinstance(tool_call["arguments"], str):
+        arguments = json.loads(tool_call["arguments"])
+    else:
+        arguments = tool_call["arguments"]
 
     for k, v in arguments.items():
         p_dsml_str = p_dsml_template.format(
diff --git a/vllm/tokenizers/deepseekv32.py b/vllm/tokenizers/deepseekv32.py
index 7466ad4076bd8..1140357cf861d 100644
--- a/vllm/tokenizers/deepseekv32.py
+++ b/vllm/tokenizers/deepseekv32.py
@@ -43,7 +43,8 @@ class DeepseekV32Tokenizer(HfTokenizer):
         thinking_mode = "thinking"
         if not thinking:
             thinking_mode = "chat"
-        messages = messages.copy()
+        conversation = kwargs.get("conversation", messages)
+        messages = conversation.copy()
         drop_thinking = True
         if tools is not None and len(tools) > 0:
             messages.insert(0, {"role": "system"})