diff --git a/Controllers/SlidesController.cs b/Controllers/SlidesController.cs
index ec802f5..fa76e97 100644
--- a/Controllers/SlidesController.cs
+++ b/Controllers/SlidesController.cs
@@ -70,6 +70,7 @@ public class SlidesController : Controller
         existing.CustomCss = slide.CustomCss;
         existing.BackgroundColor = slide.BackgroundColor;
         existing.BackgroundImage = slide.BackgroundImage;
+        existing.BackgroundSize = slide.BackgroundSize;
         existing.UpdatedAt = DateTime.UtcNow;
 
         await _db.SaveChangesAsync();