diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index b0533ceb56..78d9b44bd5 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -546,7 +546,7 @@ void GLFlat::ProcessSector(sector_t * frontsector)
 		if (x.ffloors.Size())
 		{
 			light = P_GetPlaneLight(sector, &frontsector->floorplane, false);
-			if ((!(sector->GetFlags(sector_t::floor)&PLANEF_ABSLIGHTING) || light!=&x.lightlist[0])	
+			if ((!(sector->GetFlags(sector_t::floor)&PLANEF_ABSLIGHTING) || !light->fromsector)	
 				&& (light->p_lightlevel != &frontsector->lightlevel))
 			{
 				lightlevel = *light->p_lightlevel;
diff --git a/src/p_3dfloors.cpp b/src/p_3dfloors.cpp
index cad1f16fa6..da72bc1711 100644
--- a/src/p_3dfloors.cpp
+++ b/src/p_3dfloors.cpp
@@ -584,6 +584,7 @@ void P_Recalculate3DFloors(sector_t * sector)
 		lightlist[0].extra_colormap = sector->ColorMap;
 		lightlist[0].blend = 0;
 		lightlist[0].flags = 0;
+		lightlist[0].fromsector = true;
 		
 		maxheight = sector->CenterCeiling();
 		minheight = sector->CenterFloor();
@@ -605,6 +606,7 @@ void P_Recalculate3DFloors(sector_t * sector)
 				newlight.extra_colormap = rover->GetColormap();
 				newlight.blend = rover->GetBlend();
 				newlight.flags = rover->flags;
+				newlight.fromsector = false;
 				lightlist.Push(newlight);
 			}
 			else if (i==0)
@@ -619,6 +621,7 @@ void P_Recalculate3DFloors(sector_t * sector)
 					lightlist[0].extra_colormap = rover->GetColormap();
 					lightlist[0].blend = rover->GetBlend();
 					lightlist[0].flags = rover->flags;
+					lightlist[0].fromsector = false;
 				}
 			}
 			if (rover->flags&FF_DOUBLESHADOW)
@@ -643,6 +646,7 @@ void P_Recalculate3DFloors(sector_t * sector)
 						newlight.blend = 0;
 					}
 					newlight.flags = rover->flags;
+					newlight.fromsector = false;
 					lightlist.Push(newlight);
 				}
 			}
diff --git a/src/p_3dfloors.h b/src/p_3dfloors.h
index 8d42560af0..4321ad0e5d 100644
--- a/src/p_3dfloors.h
+++ b/src/p_3dfloors.h
@@ -123,6 +123,7 @@ struct lightlist_t
 	int						flags;
 	F3DFloor*				lightsource;
 	F3DFloor*				caster;
+	bool					fromsector;
 };