diff --git a/src/processor/memory/mmio/gpu.rs b/src/processor/memory/mmio/gpu.rs
index def20b5..15ab2a6 100644
--- a/src/processor/memory/mmio/gpu.rs
+++ b/src/processor/memory/mmio/gpu.rs
@@ -24,6 +24,7 @@ pub struct Gpu {
     pub vram: Vram,
     pub oam: Oam,
     pub window: Box<dyn Renderer>,
+    is_bg_zero: Vec<bool>,
     lcdc: Lcdc,
     stat: Stat,
     mode_clock: usize,
@@ -55,6 +56,7 @@ impl Gpu {
             vram: Vram::default(),
             oam: Oam::default(),
             window,
+            is_bg_zero: vec![true; WIDTH],
             lcdc: Lcdc::default(),
             stat: Stat::default(),
             mode_clock: 0,
@@ -153,6 +155,9 @@ impl Gpu {
     }
 
     fn render_scanline(&mut self, scanline: u8) {
+        for e in &mut self.is_bg_zero {
+            *e = true;
+        }
         for x in 0..WIDTH {
             self.buffer[(scanline as usize * WIDTH) + x] = Colour::from_u8_rgb(255, 0, 255);
         }
@@ -292,9 +297,7 @@ impl Gpu {
             let x_coord = x_coord_uncorrected - 8;
             if x_coord < WIDTH {
                 let buffer_index = (scanline as usize * WIDTH) + x_coord;
-                if !object.flags.behind_bg_and_window
-                    || self.buffer[buffer_index] == self.bg_palette.zero.as_rgb()
-                {
+                if !object.flags.behind_bg_and_window || self.is_bg_zero[x_coord] {
                     self.buffer[buffer_index] = colour.as_rgb();
                 }
             }
@@ -340,6 +343,10 @@ impl Gpu {
             let msb = get_bit(msbs, 7 - tile_px_x);
             let colour = self.bg_palette.map_bits(lsb, msb);
 
+            if lsb || msb {
+                self.is_bg_zero[x] = false;
+            }
+
             self.buffer[(scanline as usize * WIDTH) + x] = colour.as_rgb();
         }
     }
diff --git a/src/processor/memory/mmio/gpu/types.rs b/src/processor/memory/mmio/gpu/types.rs
index b8ad570..a76de9f 100644
--- a/src/processor/memory/mmio/gpu/types.rs
+++ b/src/processor/memory/mmio/gpu/types.rs
@@ -125,7 +125,7 @@ impl Colour {
     }
 }
 
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 pub(super) struct Palette {
     pub(super) zero: Colour,
     pub(super) one: Colour,