Index: source/blender/gpu/shaders/gpu_shader_material.glsl
===================================================================
--- source/blender/gpu/shaders/gpu_shader_material.glsl	(revision 51011)
+++ source/blender/gpu/shaders/gpu_shader_material.glsl	(working copy)
@@ -772,6 +772,10 @@
 {
 	/* blender render normal is negated */
- 	outnormal = -normalize(normal);
+	if(gl_FrontFacing){
+        outnormal = -normalize(normal);}
+    else{
+        outnormal = normalize(normal);}
 }
 
 void mtex_rgb_blend(vec3 outcol, vec3 texcol, float fact, float facg, out vec3 incol)