diff --git a/src/playsim/actor.h b/src/playsim/actor.h
index 026a3218ea..3b5bb3bfe6 100644
--- a/src/playsim/actor.h
+++ b/src/playsim/actor.h
@@ -427,6 +427,7 @@ enum ActorFlag8
 	MF8_SEEFRIENDLYMONSTERS	= 0X08000000,	// [inkoalawetrust] Hostile monster can see friendly monsters.
 	MF8_CROSSLINECHECK	= 0x10000000,	// [MC]Enables CanCrossLine virtual
 	MF8_MASTERNOSEE		= 0x20000000,	// Don't show object in first person if their master is the current camera.
+	MF8_ADDLIGHTLEVEL	= 0x40000000,	// [MC] Actor light level is additive with sector.
 };
 
 // --- mobj.renderflags ---
diff --git a/src/rendering/hwrenderer/scene/hw_sprites.cpp b/src/rendering/hwrenderer/scene/hw_sprites.cpp
index a0190e6ed5..1affd4db0b 100644
--- a/src/rendering/hwrenderer/scene/hw_sprites.cpp
+++ b/src/rendering/hwrenderer/scene/hw_sprites.cpp
@@ -997,7 +997,7 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 	// light calculation
 
 	bool enhancedvision = false;
-	bool UseActorLight = (thing->LightLevel > -1);
+	const bool UseActorLight = (thing->LightLevel > -1);
 
 	// allow disabling of the fullbright flag by a brightmap definition
 	// (e.g. to do the gun flashes of Doom's zombies correctly.
@@ -1006,12 +1006,22 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 
 	if (fullbright)	lightlevel = 255;
 	else if (UseActorLight)
-		lightlevel = thing->LightLevel;
+	{
+		int newlevel = thing->LightLevel;
+		if (thing->flags8 & MF8_ADDLIGHTLEVEL)
+		{
+			newlevel += hw_ClampLight(rendersector->GetTexture(sector_t::ceiling) == skyflatnum ?
+				rendersector->GetCeilingLight() : rendersector->GetFloorLight());
+
+			newlevel = clamp(newlevel, 0, 255);
+		}
+		lightlevel = newlevel;
+	}
 	else
 		lightlevel = hw_ClampLight(rendersector->GetTexture(sector_t::ceiling) == skyflatnum ?
 			rendersector->GetCeilingLight() : rendersector->GetFloorLight());
 
-	foglevel = (uint8_t)clamp<short>((UseActorLight) ? thing->LightLevel : rendersector->lightlevel, 0, 255);
+	foglevel = (uint8_t)clamp<short>((UseActorLight) ? lightlevel : rendersector->lightlevel, 0, 255);
 
 	lightlevel = rendersector->CheckSpriteGlow(lightlevel, thingpos);
 
diff --git a/src/rendering/swrenderer/scene/r_opaque_pass.cpp b/src/rendering/swrenderer/scene/r_opaque_pass.cpp
index 74c4727024..48cf6a3265 100644
--- a/src/rendering/swrenderer/scene/r_opaque_pass.cpp
+++ b/src/rendering/swrenderer/scene/r_opaque_pass.cpp
@@ -956,7 +956,15 @@ namespace swrenderer
 						thingColormap = GetSpriteColorTable(thing->Sector->Colormap, thing->Sector->SpecialColors[sector_t::sprites], nc);					
 					}
 					if (thing->LightLevel > -1)
+					{
 						thinglightlevel = thing->LightLevel;
+
+						if (thing->flags8 & MF8_ADDLIGHTLEVEL)
+						{
+							thinglightlevel += thing->Sector->GetTexture(sector_t::ceiling) == skyflatnum ? thing->Sector->GetCeilingLight() : thing->Sector->GetFloorLight();
+							thinglightlevel = clamp(thinglightlevel, 0, 255);
+						}
+					}
 					if ((sprite.renderflags & RF_SPRITETYPEMASK) == RF_WALLSPRITE)
 					{
 						RenderWallSprite::Project(Thread, thing, sprite.pos, sprite.tex, sprite.spriteScale, sprite.renderflags, thinglightlevel, foggy, thingColormap);
diff --git a/src/scripting/thingdef_data.cpp b/src/scripting/thingdef_data.cpp
index 3f5a84e3b3..0f7abaac6a 100644
--- a/src/scripting/thingdef_data.cpp
+++ b/src/scripting/thingdef_data.cpp
@@ -342,6 +342,7 @@ static FFlagDef ActorFlagDefs[]=
 	DEFINE_FLAG(MF8, SEEFRIENDLYMONSTERS, AActor, flags8),
 	DEFINE_FLAG(MF8, CROSSLINECHECK, AActor, flags8),
 	DEFINE_FLAG(MF8, MASTERNOSEE, AActor, flags8),
+	DEFINE_FLAG(MF8, ADDLIGHTLEVEL, AActor, flags8),
 
 	// Effect flags
 	DEFINE_FLAG(FX, VISIBILITYPULSE, AActor, effects),