diff --git a/allg5ui/rendererfactory.go b/allg5ui/rendererfactory.go
index 148924a..f55831b 100644
--- a/allg5ui/rendererfactory.go
+++ b/allg5ui/rendererfactory.go
@@ -13,6 +13,7 @@ type rendererFactory struct{}
 
 func (f rendererFactory) New(title string, width, height int, opts ui.NewRendererOptions) (ui.Renderer, error) {
 	renderer, err := NewRenderer(width, height, allg5.NewDisplayOptions{
+		Frameless: opts.Borderless,
 		Resizable: opts.Resizable,
 		Vsync:     opts.VSync,
 	})
diff --git a/sdlui/renderer.go b/sdlui/renderer.go
index 1558eb2..ce72923 100644
--- a/sdlui/renderer.go
+++ b/sdlui/renderer.go
@@ -33,9 +33,10 @@ var _ ui.Renderer = &Renderer{}
 var _ ui.Texture = &Renderer{}
 
 type NewRendererOptions struct {
-	Location  sdl.Point
-	Resizable bool
-	VSync     bool
+	Borderless bool
+	Location   sdl.Point
+	Resizable  bool
+	VSync      bool
 }
 
 func NewRenderer(title string, width, height int32, opts NewRendererOptions) (*Renderer, error) {
@@ -57,6 +58,9 @@ func NewRenderer(title string, width, height int32, opts NewRendererOptions) (*R
 	}
 	sdl.SetHint(sdl.HINT_RENDER_SCALE_QUALITY, "1")
 	windowFlags := uint32(sdl.WINDOW_SHOWN)
+	if opts.Borderless {
+		windowFlags |= sdl.WINDOW_BORDERLESS
+	}
 	if opts.Resizable {
 		windowFlags |= sdl.WINDOW_RESIZABLE
 	}
diff --git a/sdlui/rendererfactory.go b/sdlui/rendererfactory.go
index 7ee84fd..78f55c7 100644
--- a/sdlui/rendererfactory.go
+++ b/sdlui/rendererfactory.go
@@ -18,8 +18,9 @@ func (f rendererFactory) New(title string, width, height int, opts ui.NewRendere
 		location.Y = int32(opts.Location.Y)
 	}
 	return NewRenderer(title, int32(width), int32(height), NewRendererOptions{
-		Location:  location,
-		Resizable: opts.Resizable,
-		VSync:     opts.VSync,
+		Borderless: opts.Borderless,
+		Location:   location,
+		Resizable:  opts.Resizable,
+		VSync:      opts.VSync,
 	})
 }
diff --git a/ui/rendererfactory.go b/ui/rendererfactory.go
index 07d338a..5490e4d 100644
--- a/ui/rendererfactory.go
+++ b/ui/rendererfactory.go
@@ -40,7 +40,8 @@ func SetRendererFactory(factory RendererFactory) {
 
 // NewRendererOptions provides options when creating a new renderer.
 type NewRendererOptions struct {
-	Location  *geom.PointF32
-	Resizable bool
-	VSync     bool
+	Location   *geom.PointF32
+	Borderless bool
+	Resizable  bool
+	VSync      bool
 }