diff --git a/shader/main3d.frag.glsl b/shader/main3d.frag.glsl
index d48b1de..45e4e74 100644
--- a/shader/main3d.frag.glsl
+++ b/shader/main3d.frag.glsl
@@ -28,7 +28,6 @@ vec4 sampleSampler(in const sampler2D tex, in const TileConf tileConf, in vec2 u
   // https://github.com/rt64/rt64/blob/61aa08f517cd16c1dbee4e097768b08e2a060307/src/shaders/TextureSampler.hlsli#L156-L276
   const ivec2 texSize = textureSize(tex, 0);
 
-  uvCoord.y = texSize.y - uvCoord.y; // invert Y
   uvCoord *= tileConf.shift;
 
 #ifdef SIMULATE_LOW_PRECISION
diff --git a/shader/utils.glsl b/shader/utils.glsl
index 8a361d8..74a5c74 100644
--- a/shader/utils.glsl
+++ b/shader/utils.glsl
@@ -38,7 +38,7 @@ float noise(in vec2 uv)
 
 vec2 mirrorUV(const vec2 uvIn, const vec2 uvBound)
 {
-    vec2 uvMod2 = mod(uvIn, uvBound * 2.0);
+    vec2 uvMod2 = mod(uvIn, uvBound * 2.0 + 1.0);
     return mix(uvMod2, (uvBound * 2.0) - uvMod2, step(uvBound, uvMod2));
 }
 
@@ -57,7 +57,5 @@ vec4 wrappedMirrorSample(const sampler2D tex, vec2 uv, const vec2 mask, const ve
   // clamp again (mask S/T), this is also done to avoid OOB texture access
   uv = mod(uv, min(texSize, mask));
 
-  uv.y = texSize.y - uv.y - 1; // invert Y back
-
   return texelFetch(tex, ivec2(floor(uv)), 0);
 }