diff --git a/src/Skia/Avalonia.Skia/FormattedTextImpl.cs b/src/Skia/Avalonia.Skia/FormattedTextImpl.cs
index 8568c80c04..569849fa86 100644
--- a/src/Skia/Avalonia.Skia/FormattedTextImpl.cs
+++ b/src/Skia/Avalonia.Skia/FormattedTextImpl.cs
@@ -616,6 +616,7 @@ namespace Avalonia.Skia
 
             if (brush != null)
             {
+                brush = ((IMutableBrush)brush)?.ToImmutable() ?? brush;
                 _foregroundBrushes.Insert(0, new KeyValuePair<FBrushRange, IBrush>(key, brush));
             }
         }