diff --git a/ChangeLog b/ChangeLog
index 6231170336..3cde2616ae 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2005-01-13  Bill Skaggs <weskaggs@primate.ucdavis.edu>
+
+	* plug-ins/Lighting/lighting_shade.c: remove artifacts
+	when light strikes underside of bumpmapped surface;
+	should fix bug #163877.
+	
 2005-01-13  Bill Skaggs <weskaggs@primate.ucdavis.edu>
 
 	* plug-ins/bmp/bmp.h
diff --git a/plug-ins/Lighting/lighting_shade.c b/plug-ins/Lighting/lighting_shade.c
index f4e62f53c6..50b0a45543 100644
--- a/plug-ins/Lighting/lighting_shade.c
+++ b/plug-ins/Lighting/lighting_shade.c
@@ -58,7 +58,7 @@ phong_shade (GimpVector3 *position,
   if (dist != 0.0)
     gimp_vector3_mul (&l, 1.0 / dist);
 
-  nl = 2.0 * gimp_vector3_inner_product (&n, &l);
+  nl = MAX (0., 2.0 * gimp_vector3_inner_product (&n, &l));
 
   lnormal = l;
   gimp_vector3_normalize (&lnormal);
@@ -74,7 +74,7 @@ phong_shade (GimpVector3 *position,
       gimp_vector3_add (&h, &lnormal, &v);
       gimp_vector3_normalize (&h);
 
-      rv = MAX (0., gimp_vector3_inner_product (&n, &h));
+      rv = MAX (0.01, gimp_vector3_inner_product (&n, &h));
       rv = pow (rv, mapvals.material.highlight);
       rv *= nl;