diff --git a/fb/main.go b/fb/main.go
index 3248dff..316d7a1 100644
--- a/fb/main.go
+++ b/fb/main.go
@@ -24,6 +24,7 @@ func Resolution() (w int, h int) {
 }
 
 var devfb *os.File
+var width, height = Resolution()
 
 func init() {
 	var err error
@@ -40,8 +41,8 @@ func Bytes(c color.Color) []byte {
 
 func Draw(img image.Image) error {
 	buf := bufio.NewWriterSize(devfb, 1<<16)
-	for h := 0; h < Height; h++ {
-		for w := 0; w < Width; w++ {
+	for h := 0; h < height; h++ {
+		for w := 0; w < width; w++ {
 			_, err := buf.Write(Bytes(img.At(w, h)))
 			if err != nil {
 				return err