diff --git a/tests/test_litellm/litellm_core_utils/test_token_counter.py b/tests/test_litellm/litellm_core_utils/test_token_counter.py
index e3090d9751b..7019577cca0 100644
--- a/tests/test_litellm/litellm_core_utils/test_token_counter.py
+++ b/tests/test_litellm/litellm_core_utils/test_token_counter.py
@@ -1171,7 +1171,7 @@ def test_count_content_list_rejects_unknown_type():
     ],
     ids=["base64", "url", "file"],
 )
-def test_token_counter_with_anthropic_image_block(source):
+def test_token_counter_with_anthropic_image_block(source: dict[str, str]):
     """
     Anthropic-native `image` blocks must NOT raise, for every source variant.