diff --git a/docs/shader-api/fragment.glsl b/docs/shader-api/fragment.glsl
index 95107cf4d..71b29f901 100644
--- a/docs/shader-api/fragment.glsl
+++ b/docs/shader-api/fragment.glsl
@@ -13,9 +13,6 @@
 
 /*const*/ float flw_distance;
 
-/*const*/ bool flw_vertexDiffuse;
-
-bool flw_fragDiffuse;
 vec4 flw_fragColor;
 ivec2 flw_fragOverlay;
 vec2 flw_fragLight;
diff --git a/docs/shader-api/vertex.glsl b/docs/shader-api/vertex.glsl
index 169ade9ba..338923540 100644
--- a/docs/shader-api/vertex.glsl
+++ b/docs/shader-api/vertex.glsl
@@ -7,8 +7,6 @@ ivec2 flw_vertexOverlay;
 vec2 flw_vertexLight;
 vec3 flw_vertexNormal;
 
-bool flw_vertexDiffuse;
-
 /*const*/ FlwMaterial flw_material;
 
 // To be implemented by the instance shader.
diff --git a/src/main/resources/assets/flywheel/flywheel/internal/common.frag b/src/main/resources/assets/flywheel/flywheel/internal/common.frag
index 533e905f5..a88bdd6cc 100644
--- a/src/main/resources/assets/flywheel/flywheel/internal/common.frag
+++ b/src/main/resources/assets/flywheel/flywheel/internal/common.frag
@@ -10,8 +10,6 @@ uniform sampler2D _flw_diffuseTex;
 uniform sampler2D _flw_overlayTex;
 uniform sampler2D _flw_lightTex;
 
-flat in uint _flw_vertexDiffuse;
-
 out vec4 _flw_outputColor;
 
 void _flw_main() {
@@ -20,16 +18,13 @@ void _flw_main() {
     flw_fragOverlay = flw_vertexOverlay;
     flw_fragLight = flw_vertexLight;
 
-    flw_vertexDiffuse = bool(_flw_vertexDiffuse);
-    flw_fragDiffuse = flw_vertexDiffuse;
-
     flw_beginFragment();
     flw_materialFragment();
     flw_endFragment();
 
     vec4 color = flw_fragColor;
 
-    if (flw_fragDiffuse) {
+    if (flw_material.diffuse) {
         float diffuseFactor;
         if (flw_constantAmbientLight == 1u) {
             diffuseFactor = diffuseNether(flw_vertexNormal);
diff --git a/src/main/resources/assets/flywheel/flywheel/internal/common.vert b/src/main/resources/assets/flywheel/flywheel/internal/common.vert
index e7045f810..4cd86566e 100644
--- a/src/main/resources/assets/flywheel/flywheel/internal/common.vert
+++ b/src/main/resources/assets/flywheel/flywheel/internal/common.vert
@@ -1,10 +1,6 @@
 #include "flywheel:internal/fog_distance.glsl"
 
-flat out uint _flw_vertexDiffuse;
-
 void _flw_main(in FlwInstance instance) {
-    flw_vertexDiffuse = flw_material.diffuse;
-
     _flw_layoutVertex();
     flw_beginVertex();
     flw_instanceVertex(instance);
@@ -13,8 +9,6 @@ void _flw_main(in FlwInstance instance) {
 
     flw_vertexNormal = normalize(flw_vertexNormal);
 
-    _flw_vertexDiffuse = uint(flw_vertexDiffuse);
-
     flw_distance = fogDistance(flw_vertexPos.xyz, flw_cameraPos.xyz, flw_fogShape);
     gl_Position = flw_viewProjection * flw_vertexPos;
 }
diff --git a/src/main/resources/assets/flywheel/flywheel/internal/common_api_impl.frag b/src/main/resources/assets/flywheel/flywheel/internal/common_api_impl.frag
index dea3ab9a2..3423727df 100644
--- a/src/main/resources/assets/flywheel/flywheel/internal/common_api_impl.frag
+++ b/src/main/resources/assets/flywheel/flywheel/internal/common_api_impl.frag
@@ -11,8 +11,6 @@ in vec3 flw_vertexNormal;
 
 in float flw_distance;
 
-bool flw_vertexDiffuse;
-
 vec4 flw_sampleColor;
 
 FlwMaterial flw_material;
diff --git a/src/main/resources/assets/flywheel/flywheel/internal/common_api_impl.vert b/src/main/resources/assets/flywheel/flywheel/internal/common_api_impl.vert
index e17c0084f..2cddb2e42 100644
--- a/src/main/resources/assets/flywheel/flywheel/internal/common_api_impl.vert
+++ b/src/main/resources/assets/flywheel/flywheel/internal/common_api_impl.vert
@@ -12,6 +12,4 @@ out vec3 flw_vertexNormal;
 
 out float flw_distance;
 
-bool flw_vertexDiffuse;
-
 FlwMaterial flw_material;