diff --git a/Source/Core/VideoCommon/ConstantManager.h b/Source/Core/VideoCommon/ConstantManager.h
index 14c8732580..ab399f3a4e 100644
--- a/Source/Core/VideoCommon/ConstantManager.h
+++ b/Source/Core/VideoCommon/ConstantManager.h
@@ -103,6 +103,8 @@ struct alignas(16) VertexShaderConstants
   u32 vertex_offset_posmtx;
   std::array<u32, 2> vertex_offset_colors;
   std::array<u32, 8> vertex_offset_texcoords;
+  // For custom meshes (TODO: move)
+  std::array<float4, 4> custom_transform;
 };
 
 enum class VSExpand : u32
diff --git a/Source/Core/VideoCommon/ShaderGenCommon.h b/Source/Core/VideoCommon/ShaderGenCommon.h
index 7d2c80f086..bc6ca09de2 100644
--- a/Source/Core/VideoCommon/ShaderGenCommon.h
+++ b/Source/Core/VideoCommon/ShaderGenCommon.h
@@ -319,6 +319,7 @@ static const char s_shader_uniforms[] = "\tuint    components;\n"
                                         "\tuint vertex_offset_rawcolor0;\n"
                                         "\tuint vertex_offset_rawcolor1;\n"
                                         "\tuint4 vertex_offset_rawtex[2];\n"  // std140 is pain
+                                        "\tfloat4 custom_transform[4];\n"
                                         "\t#define xfmem_texMtxInfo(i) (xfmem_pack1[(i)].x)\n"
                                         "\t#define xfmem_postMtxInfo(i) (xfmem_pack1[(i)].y)\n"
                                         "\t#define xfmem_color(i) (xfmem_pack1[(i)].z)\n"