diff --git a/src/lib/model/shader/fragment.ts b/src/lib/model/shader/fragment.ts
index 1b6bf0c..d7a96e7 100644
--- a/src/lib/model/shader/fragment.ts
+++ b/src/lib/model/shader/fragment.ts
@@ -77,6 +77,11 @@ void combineOpaqueMod2x(inout vec4 color, in vec4 tex0, in vec4 tex1) {
 void combineOpaqueMod2xNa(inout vec4 color, in vec4 tex0, in vec4 tex1) {
   color.rgb = (color.rgb * tex0.rgb) * tex1.rgb * 2.0;
 }
+
+void combineModMod(inout vec4 color, in vec4 tex0, in vec4 tex1) {
+  color.rgb = (color.rgb * tex0.rgb) * tex1.rgb;
+  color.a = (color.a * tex0.a) * tex1.a;
+}
 `;
 
 const FRAGMENT_SHADER_MAIN_ALPHATEST = `
@@ -175,6 +180,7 @@ const FRAGMENT_SHADER = {
   [M2_FRAGMENT_SHADER.FRAGMENT_OPAQUE_MOD2XNA]: createFragmentShader(2, 'combineOpaqueMod2xNa'),
   [M2_FRAGMENT_SHADER.FRAGMENT_OPAQUE_ADDNA]: createFragmentShader(2, 'combineOpaqueAddNa'),
   [M2_FRAGMENT_SHADER.FRAGMENT_OPAQUE_MOD]: createFragmentShader(2, 'combineOpaqueMod'),
+  [M2_FRAGMENT_SHADER.FRAGMENT_MOD_MOD]: createFragmentShader(2, 'combineModMod'),
   [M2_FRAGMENT_SHADER.FRAGMENT_UNKNOWN]: createFragmentShader(0, ''),
 };