diff --git a/tests/test_litellm/litellm_core_utils/llm_cost_calc/test_llm_cost_calc_utils.py b/tests/test_litellm/litellm_core_utils/llm_cost_calc/test_llm_cost_calc_utils.py
index 814d0f23a6..65e3dbec8b 100644
--- a/tests/test_litellm/litellm_core_utils/llm_cost_calc/test_llm_cost_calc_utils.py
+++ b/tests/test_litellm/litellm_core_utils/llm_cost_calc/test_llm_cost_calc_utils.py
@@ -438,9 +438,9 @@ def test_string_cost_values_edge_cases():
 
     # Expected costs:
     # Prompt: 1000 * 1e-6 + 100 * 0 (invalid string becomes 0)
-    # Completion: 500 * 2e-6 (text_tokens == completion_tokens, so is_text_tokens_total=True, no separate audio cost)
+    # Completion: 500 * 2e-6 + 50 * 2e-6 (audio tokens fall back to base cost when output_cost_per_audio_token is None)
     expected_prompt_cost = 1000 * 1e-6
-    expected_completion_cost = 500 * 2e-6
+    expected_completion_cost = 500 * 2e-6 + 50 * 2e-6
 
     assert round(prompt_cost, 12) == round(expected_prompt_cost, 12)
     assert round(completion_cost, 12) == round(expected_completion_cost, 12)