diff --git a/Program.cs b/Program.cs
index ae35134..7b6aeaf 100644
--- a/Program.cs
+++ b/Program.cs
@@ -1,6 +1,7 @@
 using OpenTK.Graphics.OpenGL4;
 using OpenTK.Mathematics;
 using OpenTK.Windowing.Common;
+using OpenTK.Windowing.Common.Input;
 using OpenTK.Windowing.Desktop;
 using OpenTK.Windowing.GraphicsLibraryFramework;
 // https://docs.sixlabors.com/api/ImageSharp/SixLabors.ImageSharp.Image.html
@@ -503,6 +504,18 @@ public static class Util {
     return texture;
   }
 
+  public static OpenTK.Windowing.Common.Input.Image[] RenderAppIcon() {
+    Font font = SystemFonts.CreateFont("MS PMincho", 64, FontStyle.Bold);
+    TextOptions options = new(font);
+    Image<Rgba32> image = MakeImage(64, 64);
+    IBrush brush = Brushes.Solid(Color.Black);
+    image.Mutate(x => x.DrawText(options, "撮", brush));
+    byte[] pixelBytes = new byte[64 * 64 * 4];
+    image.CopyPixelDataTo(pixelBytes);
+    OpenTK.Windowing.Common.Input.Image opentkImage = new(64, 64, pixelBytes);
+    return new OpenTK.Windowing.Common.Input.Image[]{ opentkImage };
+  }
+
   public static Texture RenderStar(float radius) {
     IPath path = new Star(x: radius, y: radius, prongs: 5, innerRadii: radius * 0.4f, outerRadii: radius, angle: Util.PI);
     Image<Rgba32> image = MakeImage(path.Bounds.Width, path.Bounds.Height);
@@ -894,8 +907,8 @@ static class Program {
     nwSettings.Size = new Vector2i(bestMonitor.WorkArea.Size.X - 2, bestMonitor.WorkArea.Size.Y - 32);
     nwSettings.MinimumSize = UiGeometry.MIN_WINDOW_SIZE;
     nwSettings.Title = "Totte";
-    nwSettings.IsEventDriven = true;
-    // FIXME: nwSettings.Icon = ...
+    nwSettings.IsEventDriven = false;
+    nwSettings.Icon = new WindowIcon(Util.RenderAppIcon());
 
     using (Game game = new(gwSettings, nwSettings)) {
       game.Run();