diff --git a/openhands/core/message.py b/openhands/core/message.py
index 325b388474..6e35991c5f 100644
--- a/openhands/core/message.py
+++ b/openhands/core/message.py
@@ -72,12 +72,14 @@ class Message(BaseModel):
 
 
 def format_messages(
-    messages: Union[Message, list[Message]], with_images: bool
+    messages: Union[Message, list[Message]],
+    with_images: bool,
+    with_prompt_caching: bool,
 ) -> list[dict]:
     if not isinstance(messages, list):
         messages = [messages]
 
-    if with_images:
+    if with_images or with_prompt_caching:
         return [message.model_dump() for message in messages]
 
     converted_messages = []
@@ -113,4 +115,5 @@ def format_messages(
                     'content': content_str,
                 }
             )
+
     return converted_messages
diff --git a/openhands/llm/llm.py b/openhands/llm/llm.py
index 771522802a..553382e0e5 100644
--- a/openhands/llm/llm.py
+++ b/openhands/llm/llm.py
@@ -597,4 +597,6 @@ class LLM:
     def format_messages_for_llm(
         self, messages: Union[Message, list[Message]]
     ) -> list[dict]:
-        return format_messages(messages, self.vision_is_active())
+        return format_messages(
+            messages, self.vision_is_active(), self.is_caching_prompt_active()
+        )
diff --git a/tests/integration/conftest.py b/tests/integration/conftest.py
index e4c18e9150..9b8387c9db 100644
--- a/tests/integration/conftest.py
+++ b/tests/integration/conftest.py
@@ -185,7 +185,9 @@ def mock_user_response(*args, test_name, **kwargs):
 def mock_completion(*args, test_name, **kwargs):
     global cur_id
     messages = kwargs['messages']
-    plain_messages = format_messages(messages, with_images=False)
+    plain_messages = format_messages(
+        messages, with_images=False, with_prompt_caching=False
+    )
     message_str = message_separator.join(msg['content'] for msg in plain_messages)
 
     # this assumes all response_(*).log filenames are in numerical order, starting from one