diff --git a/app/headless/headless.go b/app/headless/headless.go
index df56295b..f7885659 100644
--- a/app/headless/headless.go
+++ b/app/headless/headless.go
@@ -45,6 +45,7 @@ func NewWindow(width, height int) (*Window, error) {
 		if err != nil {
 			return err
 		}
+		dev.Viewport(0, 0, width, height)
 		fboTex, err := dev.NewTexture(
 			backend.TextureFormatSRGB,
 			width, height,