diff --git a/tests/llm_translation/test_bedrock_completion.py b/tests/llm_translation/test_bedrock_completion.py
index 6b0c29e8fb1..fa22ff6b392 100644
--- a/tests/llm_translation/test_bedrock_completion.py
+++ b/tests/llm_translation/test_bedrock_completion.py
@@ -2712,6 +2712,10 @@ def test_bedrock_top_k_param(model, expected_params):
         data = json.loads(mock_post.call_args.kwargs["data"])
         if "mistral" in model:
             assert data["top_k"] == 2
+        elif expected_params == {}:
+            # Models that don't support top_k produce no additionalModelRequestFields;
+            # the empty block is now omitted entirely rather than sent as `{}`.
+            assert "additionalModelRequestFields" not in data
         else:
             assert data["additionalModelRequestFields"] == expected_params