diff --git a/ai-service/app/services/metadata_field_definition_service.py b/ai-service/app/services/metadata_field_definition_service.py
index 134799c..577cf20 100644
--- a/ai-service/app/services/metadata_field_definition_service.py
+++ b/ai-service/app/services/metadata_field_definition_service.py
@@ -9,7 +9,7 @@ import uuid
 from datetime import datetime
 from typing import Any
 
-from sqlalchemy import select, func, cast, text
+from sqlalchemy import select, func, cast, text, any_
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.ext.asyncio import AsyncSession
 from sqlmodel import col
@@ -63,10 +63,7 @@ class MetadataFieldDefinitionService:
         
         if scope:
             stmt = stmt.where(
-                func.jsonb_contains(
-                    cast(MetadataFieldDefinition.scope, JSONB),
-                    func.cast(f'["{scope}"]', JSONB)
-                )
+                cast(MetadataFieldDefinition.scope, JSONB).op('?')(scope)
             )
         
         stmt = stmt.order_by(col(MetadataFieldDefinition.created_at).desc())
@@ -279,10 +276,7 @@ class MetadataFieldDefinitionService:
         
         if scope:
             stmt = stmt.where(
-                func.jsonb_contains(
-                    cast(MetadataFieldDefinition.scope, JSONB),
-                    func.cast(f'["{scope}"]', JSONB)
-                )
+                cast(MetadataFieldDefinition.scope, JSONB).op('?')(scope)
             )
         
         stmt = stmt.order_by(col(MetadataFieldDefinition.created_at).desc())