diff --git a/src/Squidex.Domain.Apps.Entities/Contents/Text/IndexState.cs b/src/Squidex.Domain.Apps.Entities/Contents/Text/IndexState.cs
index 8322a6a8a..7be407a84 100644
--- a/src/Squidex.Domain.Apps.Entities/Contents/Text/IndexState.cs
+++ b/src/Squidex.Domain.Apps.Entities/Contents/Text/IndexState.cs
@@ -5,7 +5,6 @@
 //  All rights reserved. Licensed under the MIT license.
 // ==========================================================================
 
-using System;
 using Lucene.Net.Documents;
 using Lucene.Net.Index;
 using Lucene.Net.Util;