diff --git a/litellm/integrations/custom_guardrail.py b/litellm/integrations/custom_guardrail.py
index fadf6e4f804..f56ff3f1b1b 100644
--- a/litellm/integrations/custom_guardrail.py
+++ b/litellm/integrations/custom_guardrail.py
@@ -626,9 +626,6 @@ class CustomGuardrail(CustomLogger):
     def uses_apply_guardrail_interface(self) -> bool:
         return type(self).apply_guardrail is not CustomGuardrail.apply_guardrail
 
-    def supports_streaming_call_type(self, call_type: CallTypes) -> bool:
-        return call_type in self.supported_streaming_call_types
-
     def _deployment_pre_call_target(self) -> "CustomLogger":
         if not self.uses_apply_guardrail_interface():
             return self
diff --git a/litellm/proxy/utils.py b/litellm/proxy/utils.py
index 1c680f095d1..4788efe9216 100644
--- a/litellm/proxy/utils.py
+++ b/litellm/proxy/utils.py
@@ -1753,35 +1753,23 @@ class ProxyLogging:
         return caps
 
     @staticmethod
-    def _stream_requires_guardrail_translation(user_api_key_dict: UserAPIKeyAuth) -> bool:
-        from litellm.litellm_core_utils.api_route_to_call_types import (
-            get_call_types_for_route,
-        )
-
-        route: Final = user_api_key_dict.request_route
-        if not route:
-            return False
-        call_types: Final = get_call_types_for_route(route)
-        if not call_types:
-            return False
-        return call_types[0] in NON_OPENAI_STREAM_GUARDRAIL_TRANSLATION_CALL_TYPES
-
-    @staticmethod
-    def _guardrail_supports_streaming_route(
-        guardrail: CustomGuardrail,
+    def _stream_guardrail_translation_call_type(
         user_api_key_dict: UserAPIKeyAuth,
-    ) -> bool:
+    ) -> CallTypes | None:
         from litellm.litellm_core_utils.api_route_to_call_types import (
             get_call_types_for_route,
         )
 
         route: Final = user_api_key_dict.request_route
         if not route:
-            return False
+            return None
         call_types: Final = get_call_types_for_route(route)
         if not call_types:
-            return False
-        return any(guardrail.supports_streaming_call_type(call_type) for call_type in call_types)
+            return None
+        call_type: Final = call_types[0]
+        if call_type not in NON_OPENAI_STREAM_GUARDRAIL_TRANSLATION_CALL_TYPES:
+            return None
+        return call_type
 
     @staticmethod
     def has_post_call_response_headers_callbacks() -> bool:
@@ -2744,7 +2732,7 @@ class ProxyLogging:
         request_data = _check_and_merge_model_level_guardrails(data=request_data, llm_router=llm_router)
 
         current_response = response
-        stream_needs_translation: Final = ProxyLogging._stream_requires_guardrail_translation(user_api_key_dict)
+        stream_translation_call_type: Final = ProxyLogging._stream_guardrail_translation_call_type(user_api_key_dict)
 
         for resolved_callback, kind in caps.iterator_overrides:
             if isinstance(resolved_callback, CustomGuardrail):
@@ -2757,14 +2745,11 @@ class ProxyLogging:
                 "apply_guardrail"
                 if (
                     kind == "override"
-                    and stream_needs_translation
+                    and stream_translation_call_type is not None
                     and isinstance(resolved_callback, CustomGuardrail)
                     and resolved_callback.uses_apply_guardrail_interface()
                     and not resolved_callback.mask_response_content
-                    and not ProxyLogging._guardrail_supports_streaming_route(
-                        resolved_callback,
-                        user_api_key_dict,
-                    )
+                    and stream_translation_call_type not in resolved_callback.supported_streaming_call_types
                 )
                 else kind
             )
diff --git a/tests/test_litellm/proxy/test_proxy_logging_hook_detection.py b/tests/test_litellm/proxy/test_proxy_logging_hook_detection.py
index 12817902765..51fc20e7a33 100644
--- a/tests/test_litellm/proxy/test_proxy_logging_hook_detection.py
+++ b/tests/test_litellm/proxy/test_proxy_logging_hook_detection.py
@@ -51,17 +51,6 @@ def test_has_streaming_callbacks_detects_guardrails(monkeypatch):
     assert ProxyLogging.has_streaming_callbacks() is True
 
 
-def test_custom_guardrail_streaming_call_type_capability_is_opt_in():
-    from litellm.types.utils import CallTypes
-
-    class _ProtocolAwareGuardrail(CustomGuardrail):
-        supported_streaming_call_types = frozenset({CallTypes.anthropic_messages})
-
-    assert CustomGuardrail().supports_streaming_call_type(CallTypes.anthropic_messages) is False
-    assert _ProtocolAwareGuardrail().supports_streaming_call_type(CallTypes.anthropic_messages) is True
-    assert _ProtocolAwareGuardrail().supports_streaming_call_type(CallTypes.aresponses) is False
-
-
 @pytest.mark.asyncio
 async def test_post_call_response_headers_hook_returns_early_without_callbacks(
     monkeypatch,
@@ -244,27 +233,28 @@ def _streaming_logging_obj():
     )
 
 
-def test_stream_requires_guardrail_translation_route_detection():
+def test_stream_guardrail_translation_call_type_route_detection():
     from litellm.proxy._types import UserAPIKeyAuth
+    from litellm.types.utils import CallTypes
 
     assert (
-        ProxyLogging._stream_requires_guardrail_translation(
+        ProxyLogging._stream_guardrail_translation_call_type(
             UserAPIKeyAuth(api_key="sk-1234", request_route="/v1/messages")
         )
-        is True
+        is CallTypes.anthropic_messages
     )
     assert (
-        ProxyLogging._stream_requires_guardrail_translation(
+        ProxyLogging._stream_guardrail_translation_call_type(
             UserAPIKeyAuth(api_key="sk-1234", request_route="/chat/completions")
         )
-        is False
+        is None
     )
-    assert ProxyLogging._stream_requires_guardrail_translation(UserAPIKeyAuth(api_key="sk-1234")) is False
+    assert ProxyLogging._stream_guardrail_translation_call_type(UserAPIKeyAuth(api_key="sk-1234")) is None
     assert (
-        ProxyLogging._stream_requires_guardrail_translation(
+        ProxyLogging._stream_guardrail_translation_call_type(
             UserAPIKeyAuth(api_key="sk-1234", request_route="/route/without/call/types")
         )
-        is False
+        is None
     )