diff --git a/tests/Squidex.Domain.Apps.Core.Tests/Schemas/FieldRegistryTests.cs b/tests/Squidex.Domain.Apps.Core.Tests/Schemas/FieldRegistryTests.cs
index 215418532..ac0b861b3 100644
--- a/tests/Squidex.Domain.Apps.Core.Tests/Schemas/FieldRegistryTests.cs
+++ b/tests/Squidex.Domain.Apps.Core.Tests/Schemas/FieldRegistryTests.cs
@@ -23,6 +23,11 @@ namespace Squidex.Domain.Apps.Core.Schemas
             {
                 return null;
             }
+
+            public override T Visit<T>(IFieldPropertiesVisitor<T> visitor)
+            {
+                return default(T);
+            }
         }
 
         [Fact]