diff --git a/ref/gl/gl2_shim/fragment.glsl.inc b/ref/gl/gl2_shim/fragment.glsl.inc
index 0e66d98a..a6d1d655 100644
--- a/ref/gl/gl2_shim/fragment.glsl.inc
+++ b/ref/gl/gl2_shim/fragment.glsl.inc
@@ -1,10 +1,20 @@
 R"(
+
+
+#if VER <= 300
+#define layout(x)
+#endif
+#if VER < 300
+#define out attribute
+#define in varying
+#define texture texture2D
+#endif
 precision mediump float;
 #if ATTR_TEXCOORD0
-uniform sampler2D uTex0;
+layout(location = 5) uniform sampler2D uTex0;
 #endif
 #if ATTR_TEXCOORD1
-uniform sampler2D uTex1;
+layout(location = 6) uniform sampler2D uTex1;
 #endif
 #if FEAT_ALPHA_TEST
 uniform float uAlphaTest;
@@ -12,7 +22,7 @@ uniform float uAlphaTest;
 #if FEAT_FOG
 uniform vec4 uFog;
 #endif
-uniform vec4 uColor;
+layout(location = 2) uniform vec4 uColor;
 #if ATTR_COLOR
 in vec4 vColor;
 #endif
@@ -25,7 +35,11 @@ in vec2 vTexCoord1;
 #if ATTR_NORMAL
 in vec2 vNormal;
 #endif
+#if VER >= 300
 out vec4 oFragColor;
+#else
+#define oFragColor gl_FragColor
+#endif
 void main()
 {
 #if ATTR_COLOR
diff --git a/ref/gl/gl2_shim/gl2_shim.c b/ref/gl/gl2_shim/gl2_shim.c
index c9358a20..47c3c4f2 100644
--- a/ref/gl/gl2_shim/gl2_shim.c
+++ b/ref/gl/gl2_shim/gl2_shim.c
@@ -18,8 +18,9 @@ GNU General Public License for more details.
 	this will only provide performance gains if vitaGL is built with DRAW_SPEEDHACK=1
 	since that makes it assume that all vertex data pointers are GPU-mapped
 */
-#ifndef XASH_GL_STATIC
+
 #include "gl_local.h"
+#ifndef XASH_GL_STATIC
 #include "gl2_shim.h"
 #include <malloc.h>
 //#include "xash3d_mathlib.h"
@@ -142,24 +143,44 @@ static char *GL_PrintInfoLog( GLhandleARB object )
 }
 
 
-static GLuint GL2_GenerateShader( const gl2wrap_prog_t *prog, GLenum type )
+static GLuint GL2_GenerateShader( gl2wrap_prog_t *prog, GLenum type )
 {
 	char *shader, shader_buf[MAX_SHADERLEN + 1];
 	char tmp[256];
 	int i;
 	GLint status, len;
-	GLuint id;
+	GLuint id, loc;
+	int version = 320;
 
 	shader = shader_buf;
 	//shader[0] = '\n';
 	shader[0] = 0;
-	Q_strncat(shader, "#version 300 es\n", MAX_SHADERLEN);
+
+	Q_snprintf(shader, MAX_SHADERLEN, "#version %d%s\n", version, version >= 300 && version < 330 ? " es":"");
+
+	Q_snprintf(tmp, sizeof( tmp ), "#define VER %d\n", version);
+	Q_strncat( shader, tmp, MAX_SHADERLEN );
 
 	for ( i = 0; i < GL2_FLAG_MAX; ++i )
 	{
 		Q_snprintf( tmp, sizeof( tmp ), "#define %s %d\n", gl2wrap_flag_name[i], prog->flags & ( 1 << i ) );
 		Q_strncat( shader, tmp, MAX_SHADERLEN );
 	}
+	loc = 0;
+	for ( i = 0; i < GL2_ATTR_MAX; ++i )
+	{
+		if ( prog->flags & ( 1 << i ) )
+		{
+			Q_snprintf( tmp, sizeof( tmp ), "#define LOC_%s %d\n", gl2wrap_flag_name[i], loc++ );
+			Q_strncat( shader, tmp, MAX_SHADERLEN );
+			prog->attridx[i] = loc;
+
+		}
+		else
+		{
+			prog->attridx[i] = -1;
+		}
+	}
 
 	if ( type == GL_FRAGMENT_SHADER_ARB )
 		Q_strncat( shader, gl2wrap_frag_src, MAX_SHADERLEN );
diff --git a/ref/gl/gl2_shim/vertex.glsl.inc b/ref/gl/gl2_shim/vertex.glsl.inc
index 79e87fbc..4a1923ac 100644
--- a/ref/gl/gl2_shim/vertex.glsl.inc
+++ b/ref/gl/gl2_shim/vertex.glsl.inc
@@ -1,23 +1,27 @@
 R"(
 
+#if VER <= 300
 #define layout(x)
-//#define in attribute
-//#define out varying
+#endif
+#if VER < 300
+#define in attribute
+#define out varying
+#endif
 
-layout(location = 0) in vec3 inPosition;
+layout(location = LOC_ATTR_POSITION) in vec3 inPosition;
 #if ATTR_COLOR
-layout(location = 1) in vec4 inColor;
-#endif
-#if ATTR_NORMAL
-layout(location = 2) in vec3 inNormal;
+layout(location = LOC_ATTR_COLOR) in vec4 inColor;
 #endif
 #if ATTR_TEXCOORD0
-layout(location = 3) in vec2 inTexCoord0;
+layout(location = LOC_ATTR_TEXCOORD0) in vec2 inTexCoord0;
 #endif
 #if ATTR_TEXCOORD1
-layout(location = 4) in vec2 inTexCoord1;
+layout(location = LOC_ATTR_TEXCOORD1) in vec2 inTexCoord1;
 #endif
 
+#if ATTR_NORMAL
+in vec3 inNormal;
+#endif
 #if ATTR_COLOR
 out vec4 vColor;
 #endif
@@ -25,7 +29,7 @@ out vec4 vColor;
 out vec2 vTexCoord0;
 #endif
 #if ATTR_TEXCOORD1
-out vec2 vTexCoord0;
+out vec2 vTexCoord1;
 #endif
 #if ATTR_NORMAL
 out vec3 vNormal;