diff --git a/NAPS2.Images.Gtk/GtkImageTransformer.cs b/NAPS2.Images.Gtk/GtkImageTransformer.cs
index 4466aa616..108d95460 100644
--- a/NAPS2.Images.Gtk/GtkImageTransformer.cs
+++ b/NAPS2.Images.Gtk/GtkImageTransformer.cs
@@ -32,10 +32,8 @@ public class GtkImageTransformer : AbstractImageTransformer<GtkImage>
         CairoHelper.SetSourcePixbuf(context, image.Pixbuf, 0, 0);
         context.Paint();
         var newImage = new GtkImage(ImageContext, new Pixbuf(surface, 0, 0, width, height));
-        // TODO: In Gdi, we convert this back to BW1. Should we do the same?
-        newImage.LogicalPixelFormat = image.LogicalPixelFormat == ImagePixelFormat.BW1
-            ? ImagePixelFormat.Gray8
-            : image.LogicalPixelFormat;
+        OptimizePixelFormat(image, ref newImage);
+        newImage.LogicalPixelFormat = image.LogicalPixelFormat;
         newImage.SetResolution(xres, yres);
         image.Dispose();
         return newImage;
diff --git a/NAPS2.Images.Mac/MacImageTransformer.cs b/NAPS2.Images.Mac/MacImageTransformer.cs
index c071a1d23..51105da9e 100644
--- a/NAPS2.Images.Mac/MacImageTransformer.cs
+++ b/NAPS2.Images.Mac/MacImageTransformer.cs
@@ -34,6 +34,7 @@ public class MacImageTransformer : AbstractImageTransformer<MacImage>
         CGRect rect = new CGRect(0, 0, image.Width, image.Height);
         using var cgImage = image.Rep.AsCGImage(ref rect, null, null);
         c.DrawImage(rect, cgImage);
+        OptimizePixelFormat(image, ref newImage);
         image.Dispose();
         return newImage;
     }
diff --git a/NAPS2.Images/Transforms/AbstractImageTransformer.cs b/NAPS2.Images/Transforms/AbstractImageTransformer.cs
index e81c53e3b..b1ddf544b 100644
--- a/NAPS2.Images/Transforms/AbstractImageTransformer.cs
+++ b/NAPS2.Images/Transforms/AbstractImageTransformer.cs
@@ -266,7 +266,7 @@ public abstract class AbstractImageTransformer<TImage> where TImage : IMemoryIma
     /// <param name="result">The result that may be replaced.</param>
     protected void OptimizePixelFormat(TImage original, ref TImage result)
     {
-        if (original.PixelFormat == ImagePixelFormat.BW1)
+        if (original.UpdateLogicalPixelFormat() == ImagePixelFormat.BW1)
         {
             result = PerformTransform(result, new BlackWhiteTransform());
         }