diff --git a/pydantic_ai_slim/pydantic_ai/models/mistral.py b/pydantic_ai_slim/pydantic_ai/models/mistral.py
index 4a29c0b7d..5372dbb08 100644
--- a/pydantic_ai_slim/pydantic_ai/models/mistral.py
+++ b/pydantic_ai_slim/pydantic_ai/models/mistral.py
@@ -45,6 +45,8 @@
     check_allow_model_requests,
     get_user_agent,
 )
+from mistralai import CompletionChunk as MistralCompletionChunk
+from mistralai.models import ChatCompletionResponse as MistralChatCompletionResponse
 
 try:
     from mistralai import (
@@ -679,13 +681,9 @@ def _validate_required_json_schema(json_dict: dict[str, Any], json_schema: dict[
 
 def _map_usage(response: MistralChatCompletionResponse | MistralCompletionChunk) -> Usage:
     """Maps a Mistral Completion Chunk or Chat Completion Response to a Usage."""
-    if response.usage:
-        return Usage(
-            request_tokens=response.usage.prompt_tokens,
-            response_tokens=response.usage.completion_tokens,
-            total_tokens=response.usage.total_tokens,
-            details=None,
-        )
+    usage = response.usage
+    if usage:
+        return Usage(usage.prompt_tokens, usage.completion_tokens, usage.total_tokens, None)
     else:
         return Usage()  # pragma: no cover