diff --git a/src/graphics.ts b/src/graphics.ts
index 9758d38a..521357e5 100644
--- a/src/graphics.ts
+++ b/src/graphics.ts
@@ -19,10 +19,8 @@ export function spr(
   h: number,
   sx: number,
   sy: number,
-  sw: number | undefined = undefined,
-  sh: number | undefined = undefined
+  sw: number,
+  sh: number
 ) {
-  sw = sw || 1.0;
-  sh = sh || 1.0;
   core.spr(x, y, w, h, sx, sy, sw, sh);
 }
diff --git a/src/main.ts b/src/main.ts
index 0a372f56..22331375 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -8,5 +8,5 @@ export function update() {}
 
 export function draw() {
   cls(0.1, 0.2, 0.3);
-  spr(0, 0, 320, 240, 0, 0);
+  spr(0, 0, 320, 240, 0, 0, 256, 256);
 }
diff --git a/src/shader.wgsl b/src/shader.wgsl
index 331b4543..06cfa782 100644
--- a/src/shader.wgsl
+++ b/src/shader.wgsl
@@ -54,5 +54,7 @@ const RES = vec2f(320.0, 240.0); // The logical resolution of the screen.
 @group(0) @binding(1) var s_diffuse : sampler;
 
 @fragment fn fs_main(in : VertexOutput)->@location(0) vec4<f32> {
-  return textureSample(t_diffuse, s_diffuse, in.tex_coords);
+  let dims = vec2f(textureDimensions(t_diffuse));
+
+  return textureSample(t_diffuse, s_diffuse, in.tex_coords / dims);
 }