diff --git a/binaries/data/mods/mod/shaders/program.rng b/binaries/data/mods/mod/shaders/program.rng
index 0f103988cc..e23db3d77b 100644
--- a/binaries/data/mods/mod/shaders/program.rng
+++ b/binaries/data/mods/mod/shaders/program.rng
@@ -37,7 +37,7 @@
                         </zeroOrMore>
                     </element>
                 </group>
-                
+
                 <group>
                     <attribute name="type">
                         <value>glsl</value>
@@ -65,9 +65,6 @@
                                             <value>gl_MultiTexCoord5</value>
                                             <value>gl_MultiTexCoord6</value>
                                             <value>gl_MultiTexCoord7</value>
-                                            <value>CustomAttribute0</value>
-                                            <value>CustomAttribute1</value>
-                                            <value>CustomAttribute2</value>
                                         </choice>
                                     </attribute>
                                 </element>
diff --git a/binaries/data/mods/public/shaders/glsl/model_common.xml b/binaries/data/mods/public/shaders/glsl/model_common.xml
index 0eb6fef37c..fe90adb8a6 100644
--- a/binaries/data/mods/public/shaders/glsl/model_common.xml
+++ b/binaries/data/mods/public/shaders/glsl/model_common.xml
@@ -10,9 +10,9 @@
         <attrib name="a_normal" semantics="gl_Normal"/>
         <attrib name="a_uv0" semantics="gl_MultiTexCoord0"/>
 	<attrib name="a_uv1" semantics="gl_MultiTexCoord1" if="USE_AO"/>
-        <attrib name="a_skinJoints" semantics="CustomAttribute0" if="USE_GPU_SKINNING"/>
-        <attrib name="a_skinWeights" semantics="CustomAttribute1" if="USE_GPU_SKINNING"/>
-	<attrib name="a_tangent" semantics="CustomAttribute2" if="USE_INSTANCING || USE_GPU_SKINNING"/>
+        <attrib name="a_skinJoints" semantics="gl_MultiTexCoord4" if="USE_GPU_SKINNING"/>
+        <attrib name="a_skinWeights" semantics="gl_MultiTexCoord5" if="USE_GPU_SKINNING"/>
+	<attrib name="a_tangent" semantics="gl_MultiTexCoord6" if="USE_INSTANCING || USE_GPU_SKINNING"/>
     </vertex>
 
     <fragment file="glsl/model_common.fs"/>
diff --git a/binaries/data/mods/public/shaders/glsl/model_solid.xml b/binaries/data/mods/public/shaders/glsl/model_solid.xml
index 0d490086a6..bb65d5cffc 100644
--- a/binaries/data/mods/public/shaders/glsl/model_solid.xml
+++ b/binaries/data/mods/public/shaders/glsl/model_solid.xml
@@ -4,8 +4,8 @@
     <vertex file="glsl/model_common.vs">
         <stream name="pos"/>
         <attrib name="a_vertex" semantics="gl_Vertex"/>
-        <attrib name="a_skinJoints" semantics="CustomAttribute0" if="USE_GPU_SKINNING"/>
-        <attrib name="a_skinWeights" semantics="CustomAttribute1" if="USE_GPU_SKINNING"/>
+        <attrib name="a_skinJoints" semantics="gl_MultiTexCoord4" if="USE_GPU_SKINNING"/>
+        <attrib name="a_skinWeights" semantics="gl_MultiTexCoord5" if="USE_GPU_SKINNING"/>
     </vertex>
 
     <fragment file="glsl/solid.fs"/>
diff --git a/binaries/data/mods/public/shaders/glsl/model_solid_player.xml b/binaries/data/mods/public/shaders/glsl/model_solid_player.xml
index 64e279bf73..d4e12ea506 100644
--- a/binaries/data/mods/public/shaders/glsl/model_solid_player.xml
+++ b/binaries/data/mods/public/shaders/glsl/model_solid_player.xml
@@ -4,8 +4,8 @@
     <vertex file="glsl/model_common.vs">
         <stream name="pos"/>
         <attrib name="a_vertex" semantics="gl_Vertex"/>
-        <attrib name="a_skinJoints" semantics="CustomAttribute0" if="USE_GPU_SKINNING"/>
-        <attrib name="a_skinWeights" semantics="CustomAttribute1" if="USE_GPU_SKINNING"/>
+        <attrib name="a_skinJoints" semantics="gl_MultiTexCoord4" if="USE_GPU_SKINNING"/>
+        <attrib name="a_skinWeights" semantics="gl_MultiTexCoord5" if="USE_GPU_SKINNING"/>
     </vertex>
 
     <fragment file="glsl/solid_player.fs"/>
diff --git a/binaries/data/mods/public/shaders/glsl/model_solid_tex.xml b/binaries/data/mods/public/shaders/glsl/model_solid_tex.xml
index 4c221e226c..338c1fa20e 100644
--- a/binaries/data/mods/public/shaders/glsl/model_solid_tex.xml
+++ b/binaries/data/mods/public/shaders/glsl/model_solid_tex.xml
@@ -6,8 +6,8 @@
         <stream name="uv0"/>
         <attrib name="a_vertex" semantics="gl_Vertex"/>
         <attrib name="a_uv0" semantics="gl_MultiTexCoord0"/>
-        <attrib name="a_skinJoints" semantics="CustomAttribute0" if="USE_GPU_SKINNING"/>
-        <attrib name="a_skinWeights" semantics="CustomAttribute1" if="USE_GPU_SKINNING"/>
+        <attrib name="a_skinJoints" semantics="gl_MultiTexCoord4" if="USE_GPU_SKINNING"/>
+        <attrib name="a_skinWeights" semantics="gl_MultiTexCoord5" if="USE_GPU_SKINNING"/>
     </vertex>
 
     <fragment file="glsl/solid_tex.fs"/>
diff --git a/binaries/data/mods/public/shaders/glsl/model_water.xml b/binaries/data/mods/public/shaders/glsl/model_water.xml
index 3d1c61665c..fe4d1bceb6 100644
--- a/binaries/data/mods/public/shaders/glsl/model_water.xml
+++ b/binaries/data/mods/public/shaders/glsl/model_water.xml
@@ -10,7 +10,7 @@
         <attrib name="a_normal" semantics="gl_Normal"/>
         <attrib name="a_uv0" semantics="gl_MultiTexCoord0"/>
 	<attrib name="a_uv1" semantics="gl_MultiTexCoord1" if="USE_AO"/>
-	<attrib name="a_tangent" semantics="CustomAttribute2" if="USE_INSTANCING"/>
+	<attrib name="a_tangent" semantics="gl_MultiTexCoord4" if="USE_INSTANCING"/>
     </vertex>
 
     <fragment file="glsl/model_water.fs"/>
diff --git a/binaries/data/mods/public/shaders/glsl/model_waterfall.xml b/binaries/data/mods/public/shaders/glsl/model_waterfall.xml
index 651a1d07b7..e5ea48f009 100644
--- a/binaries/data/mods/public/shaders/glsl/model_waterfall.xml
+++ b/binaries/data/mods/public/shaders/glsl/model_waterfall.xml
@@ -10,7 +10,7 @@
         <attrib name="a_normal" semantics="gl_Normal"/>
         <attrib name="a_uv0" semantics="gl_MultiTexCoord0"/>
 	<attrib name="a_uv1" semantics="gl_MultiTexCoord1"/>
-	<attrib name="a_tangent" semantics="CustomAttribute2" if="USE_INSTANCING"/>
+	<attrib name="a_tangent" semantics="gl_MultiTexCoord4" if="USE_INSTANCING"/>
     </vertex>
 
     <fragment file="glsl/model_waterfall.fs"/>
diff --git a/binaries/data/mods/public/shaders/glsl/water_high.xml b/binaries/data/mods/public/shaders/glsl/water_high.xml
index ee2fe04588..2bd55be5dd 100644
--- a/binaries/data/mods/public/shaders/glsl/water_high.xml
+++ b/binaries/data/mods/public/shaders/glsl/water_high.xml
@@ -4,7 +4,7 @@
     <vertex file="glsl/water_high.vs">
         <stream name="pos"/>
         <attrib name="a_vertex" semantics="gl_Vertex"/>
-        <attrib name="a_waterInfo" semantics="CustomAttribute0"/>
+        <attrib name="a_waterInfo" semantics="gl_MultiTexCoord4"/>
     </vertex>
 
     <fragment file="glsl/water_high.fs"/>
diff --git a/binaries/data/mods/public/shaders/glsl/waves.xml b/binaries/data/mods/public/shaders/glsl/waves.xml
index eaca24613e..6f535ee105 100644
--- a/binaries/data/mods/public/shaders/glsl/waves.xml
+++ b/binaries/data/mods/public/shaders/glsl/waves.xml
@@ -5,9 +5,9 @@
         <stream name="pos"/>
         <stream name="uv0"/>
         <attrib name="a_basePosition" semantics="gl_Vertex"/>
-        <attrib name="a_apexPosition" semantics="CustomAttribute0"/>
-		<attrib name="a_splashPosition" semantics="CustomAttribute1"/>
-		<attrib name="a_retreatPosition" semantics="CustomAttribute2"/>
+        <attrib name="a_apexPosition" semantics="gl_MultiTexCoord4"/>
+		<attrib name="a_splashPosition" semantics="gl_MultiTexCoord5"/>
+		<attrib name="a_retreatPosition" semantics="gl_MultiTexCoord6"/>
         <attrib name="a_normal" semantics="gl_Normal"/>
 		<attrib name="a_uv0" semantics="gl_MultiTexCoord0"/>
    </vertex>
diff --git a/source/graphics/ShaderProgram.cpp b/source/graphics/ShaderProgram.cpp
index e05ebac604..f0e62ce9f8 100644
--- a/source/graphics/ShaderProgram.cpp
+++ b/source/graphics/ShaderProgram.cpp
@@ -102,12 +102,6 @@ GLenum ParseAttribSemantics(const CStr& str)
 	if (str == "gl_MultiTexCoord6") return 14;
 	if (str == "gl_MultiTexCoord7") return 15;
 
-	// Define some arbitrary names for user-defined attribute locations
-	// that won't conflict with any standard semantics
-	if (str == "CustomAttribute0") return 1;
-	if (str == "CustomAttribute1") return 6;
-	if (str == "CustomAttribute2") return 7;
-
 	debug_warn("Invalid attribute semantics");
 	return 0;
 }