diff --git a/src/Avalonia.Base/Media/TextFormatting/ITextSource.cs b/src/Avalonia.Base/Media/TextFormatting/ITextSource.cs
index 85641977e6..26966b37bc 100644
--- a/src/Avalonia.Base/Media/TextFormatting/ITextSource.cs
+++ b/src/Avalonia.Base/Media/TextFormatting/ITextSource.cs
@@ -5,7 +5,6 @@ namespace Avalonia.Media.TextFormatting
     /// <summary>
     /// Produces <see cref="TextRun"/> objects that are used by the <see cref="TextFormatter"/>.
     /// </summary>
-    [NotClientImplementable]
     public interface ITextSource
     {
         /// <summary>