diff --git a/source/blender/render/intern/source/rendercore.c b/source/blender/render/intern/source/rendercore.c
index 2c77d29421a..98aa265d3c6 100644
--- a/source/blender/render/intern/source/rendercore.c
+++ b/source/blender/render/intern/source/rendercore.c
@@ -794,7 +794,8 @@ float Blinn_Spec(float *n, float *l, float *v, float refrac, float spec_power )
 	ang = saacos(nh);
 
 	i= f * g * exp((double)(-(ang*ang) / (2.0*spec_power*spec_power)));
-
+	if(i<0.0) i= 0.0;
+	
 	return i;
 }