diff --git a/source/blender/render/intern/include/shading.h b/source/blender/render/intern/include/shading.h
index 8250c5631dd..2d3045fcd64 100644
--- a/source/blender/render/intern/include/shading.h
+++ b/source/blender/render/intern/include/shading.h
@@ -62,6 +62,7 @@ void shade_input_calc_viewco(struct ShadeInput *shi, float x, float y, float z,
 void shade_input_set_viewco(struct ShadeInput *shi, float x, float y, float sx, float sy, float z);
 void shade_input_set_uv(struct ShadeInput *shi);
 void shade_input_set_normals(struct ShadeInput *shi);
+void shade_input_set_vertex_normals(struct ShadeInput *shi);
 void shade_input_flip_normals(struct ShadeInput *shi);
 void shade_input_set_shade_texco(struct ShadeInput *shi);
 void shade_input_set_strand(struct ShadeInput *shi, struct StrandRen *strand, struct StrandPoint *spoint);
diff --git a/source/blender/render/intern/source/shadeinput.c b/source/blender/render/intern/source/shadeinput.c
index 81b2203cbcf..f32b1046228 100644
--- a/source/blender/render/intern/source/shadeinput.c
+++ b/source/blender/render/intern/source/shadeinput.c
@@ -841,7 +841,7 @@ void shade_input_set_normals(ShadeInput *shi)
 }
 
 /* XXX shi->flippednor messes up otherwise */
-static void shade_input_set_vertex_normals(ShadeInput *shi)
+void shade_input_set_vertex_normals(ShadeInput *shi)
 {
 	float u= shi->u, v= shi->v;
 	float l= 1.0f+u+v;
diff --git a/source/blender/render/intern/source/zbuf.c b/source/blender/render/intern/source/zbuf.c
index a3d3a65cccc..f6ccb025fe7 100644
--- a/source/blender/render/intern/source/zbuf.c
+++ b/source/blender/render/intern/source/zbuf.c
@@ -3766,7 +3766,10 @@ static void shade_tra_samples_fill(ShadeSample *ssamp, int x, int y, int z, int
 					shi->samplenr= R.shadowsamplenr[shi->thread]++;
 					shade_input_set_viewco(shi, x, y, xs, ys, (float)z);
 					shade_input_set_uv(shi);
-					shade_input_set_normals(shi);
+					if(shi_inc==0)
+						shade_input_set_normals(shi);
+					else /* XXX shi->flippednor messes up otherwise */
+						shade_input_set_vertex_normals(shi);
 					
 					shi_inc= 1;
 				}