diff --git a/src/marvin/types.py b/src/marvin/types.py
index f663ee81a..104948750 100644
--- a/src/marvin/types.py
+++ b/src/marvin/types.py
@@ -161,6 +161,8 @@ class ResponseModel(MarvinType):
 
 
 class ChatRequest(Prompt[T]):
+    model_config = dict(extra="allow")
+
     model: str = Field(default_factory=lambda: settings.openai.chat.completions.model)
     frequency_penalty: Optional[
         Annotated[float, Field(strict=True, ge=-2.0, le=2.0)]
@@ -177,6 +179,8 @@ class ChatRequest(Prompt[T]):
     )
     top_p: Optional[Annotated[float, Field(strict=True, ge=0, le=1)]] = 1
     user: Optional[str] = None
+    logprobs: Optional[bool] = None
+    max_completion_tokens: Optional[Annotated[int, Field(strict=True, ge=1)]] = None
 
 
 class TranscriptRequest(MarvinType):
diff --git a/tests/ai/vision/test_caption.py b/tests/ai/vision/test_caption.py
index a8b2e7bbc..ea6df3f99 100644
--- a/tests/ai/vision/test_caption.py
+++ b/tests/ai/vision/test_caption.py
@@ -40,10 +40,13 @@ def test_two_cities(self):
             "https://images.unsplash.com/photo-1617581629397-a72507c3de9e"
         )
 
-        result = marvin.caption([img_ny, img_dc], instructions="what city is this?")
+        result = marvin.caption([img_ny, img_dc], instructions="what cities are these?")
 
         assert_equal(
             result,
             "New York City; Washington DC",
-            instructions="A caption was generated for two images. Ensure it mentions both cities.",
+            instructions=(
+                "A caption was generated for two images. Ensure it mentions both cities"
+                " but don't enforce the exact text, i.e. D.C. ~= Washington DC"
+            ),
         )
diff --git a/tests/beta/assistants/test_assistants.py b/tests/beta/assistants/test_assistants.py
index 60faefffb..464418e0a 100644
--- a/tests/beta/assistants/test_assistants.py
+++ b/tests/beta/assistants/test_assistants.py
@@ -13,6 +13,9 @@ def mocked_client():
     return client
 
 
+pytest.skip("Assistants API is not stable", allow_module_level=True)
+
+
 @pytest.fixture(autouse=True)
 def mock_get_client(monkeypatch):
     # Use monkeypatch to replace get_client with special_get_client