diff --git a/litellm/types/guardrails.py b/litellm/types/guardrails.py
index 02dee40f2a3..81ac515b54d 100644
--- a/litellm/types/guardrails.py
+++ b/litellm/types/guardrails.py
@@ -1215,6 +1215,8 @@ class ApplyGuardrailResponse(BaseModel):
 
 
 class PatchGuardrailRequest(BaseModel):
+    model_config = ConfigDict(extra="forbid")
+
     guardrail_name: str | None = None
     litellm_params: BaseLitellmParams | None = None
     guardrail_info: dict[str, Any] | None = None
diff --git a/tests/test_litellm/proxy/guardrails/test_guardrail_endpoints.py b/tests/test_litellm/proxy/guardrails/test_guardrail_endpoints.py
index 530f8ffd854..5cd4f747449 100644
--- a/tests/test_litellm/proxy/guardrails/test_guardrail_endpoints.py
+++ b/tests/test_litellm/proxy/guardrails/test_guardrail_endpoints.py
@@ -80,6 +80,21 @@ MOCK_PATCH_REQUEST = PatchGuardrailRequest(
 )
 
 
+def test_patch_guardrail_request_rejects_create_body_shape():
+    """Do not silently accept the nested POST /guardrails request body."""
+    from pydantic import ValidationError
+
+    with pytest.raises(ValidationError, match="extra_forbidden"):
+        PatchGuardrailRequest.model_validate(
+            {
+                "guardrail": {
+                    "guardrail_name": "nested-name",
+                    "litellm_params": {},
+                }
+            }
+        )
+
+
 @pytest.fixture
 def mock_prisma_client(mocker):
     """Mock Prisma client for testing"""