diff --git a/tests/test_litellm/llms/openrouter/responses/test_openrouter_responses_transformation.py b/tests/test_litellm/llms/openrouter/responses/test_openrouter_responses_transformation.py
index 544ec1ec719..62c372a3d93 100644
--- a/tests/test_litellm/llms/openrouter/responses/test_openrouter_responses_transformation.py
+++ b/tests/test_litellm/llms/openrouter/responses/test_openrouter_responses_transformation.py
@@ -60,11 +60,16 @@ class TestOpenRouterResponsesAPIConfig:
         )
         assert headers["Authorization"] == "Bearer sk-or-test-key"
 
-    def test_validate_environment_raises_without_key(self):
+    def test_validate_environment_raises_without_key(self, monkeypatch):
         """validate_environment should raise when no API key is available."""
         config = OpenRouterResponsesAPIConfig()
         from litellm.types.router import GenericLiteLLMParams
 
+        # Clear any globally set API keys so the validation correctly raises
+        monkeypatch.setattr(litellm, "api_key", None)
+        monkeypatch.delenv("OPENROUTER_API_KEY", raising=False)
+        monkeypatch.delenv("OR_API_KEY", raising=False)
+
         try:
             config.validate_environment(
                 headers={},