diff --git a/api/src/backend/api/tests/test_views.py b/api/src/backend/api/tests/test_views.py
index 92d7002761..2cf93af2ef 100644
--- a/api/src/backend/api/tests/test_views.py
+++ b/api/src/backend/api/tests/test_views.py
@@ -5485,16 +5485,8 @@ class TestLighthouseConfigViewSet:
             assert any(field in error["source"]["pointer"] for error in errors)
 
     def test_lighthouse_config_create_duplicate(
-        self, authenticated_client, valid_config_payload
+        self, authenticated_client, valid_config_payload, lighthouse_config_fixture
     ):
-        # Create first config
-        response = authenticated_client.post(
-            reverse("lighthouseconfig-list"),
-            data=valid_config_payload,
-            content_type=API_JSON_CONTENT_TYPE,
-        )
-        assert response.status_code == status.HTTP_201_CREATED
-
         # Try to create second config for same tenant
         response = authenticated_client.post(
             reverse("lighthouseconfig-list"),
@@ -5503,7 +5495,7 @@ class TestLighthouseConfigViewSet:
         )
         assert response.status_code == status.HTTP_400_BAD_REQUEST
         assert (
-            "AI configuration already exists for this tenant"
+            "Lighthouse configuration already exists for this tenant"
             in response.json()["errors"][0]["detail"]
         )
 
diff --git a/api/src/backend/api/v1/serializers.py b/api/src/backend/api/v1/serializers.py
index 4f8b44ccd2..504fc6f824 100644
--- a/api/src/backend/api/v1/serializers.py
+++ b/api/src/backend/api/v1/serializers.py
@@ -7,6 +7,7 @@ from django.contrib.auth.models import update_last_login
 from django.contrib.auth.password_validation import validate_password
 from drf_spectacular.utils import extend_schema_field
 from jwt.exceptions import InvalidKeyError
+from rest_framework.validators import UniqueTogetherValidator
 from rest_framework_json_api import serializers
 from rest_framework_json_api.serializers import ValidationError
 from rest_framework_simplejwt.exceptions import TokenError
@@ -2181,16 +2182,13 @@ class LighthouseConfigCreateSerializer(RLSSerializer, BaseWriteSerializer):
             "business_context",
             "is_active",
         ]
-
-    def validate(self, attrs):
-        tenant_id = self.context.get("request").tenant_id
-        if LighthouseConfig.objects.filter(tenant_id=tenant_id).exists():
-            raise serializers.ValidationError(
-                {
-                    "tenant_id": "AI configuration already exists for this tenant. Use PUT to update."
-                }
+        validators = [
+            UniqueTogetherValidator(
+                queryset=LighthouseConfig.objects.all(),
+                fields=["name"],
+                message="Lighthouse configuration already exists for this tenant.",
             )
-        return super().validate(attrs)
+        ]
 
     def create(self, validated_data):
         api_key = validated_data.pop("api_key")