diff --git a/src/gl/scene/gl_drawinfo.h b/src/gl/scene/gl_drawinfo.h
index 8f0e0dea4..7f0c8371d 100644
--- a/src/gl/scene/gl_drawinfo.h
+++ b/src/gl/scene/gl_drawinfo.h
@@ -73,8 +73,8 @@ struct FDrawInfo : public HWDrawInfo
 
 	// Flat drawer
 	void DrawFlat(GLFlat *flat, int pass, bool trans) override;	// trans only has meaning for GLPASS_LIGHTSONLY
-	void DrawSkyboxSector(GLFlat *flat, int pass, bool processlights);
-	void DrawSubsectors(GLFlat *flat, int pass, bool processlights, bool istrans);
+	void DrawSkyboxSector(GLFlat *flat, int pass);
+	void DrawSubsectors(GLFlat *flat, int pass, bool istrans);
 	void DrawSubsector(GLFlat *flat, subsector_t * sub);
 
 	// Sprite drawer
diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index 1d878bc64..98314af8a 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -104,7 +104,7 @@ void FDrawInfo::DrawSubsector(GLFlat *flat, subsector_t * sub)
 //
 //==========================================================================
 
-void FDrawInfo::DrawSubsectors(GLFlat *flat, int pass, bool processlights, bool istrans)
+void FDrawInfo::DrawSubsectors(GLFlat *flat, int pass, bool istrans)
 {
 	int dli = flat->dynlightindex;
 	auto vcount = flat->sector->ibocount;
@@ -112,15 +112,12 @@ void FDrawInfo::DrawSubsectors(GLFlat *flat, int pass, bool processlights, bool
 	gl_RenderState.Apply();
 	auto iboindex = flat->iboindex;
 
-	if (processlights) 
-	{
-		if (screen->hwcaps & RFL_BUFFER_STORAGE)
-		{
-			flat->SetupLights(this, flat->sector->lighthead, lightdata, flat->sector->PortalGroup);
-		}
-		gl_RenderState.ApplyLightIndex(flat->dynlightindex);
-	}
 
+	if (screen->hwcaps & RFL_BUFFER_STORAGE)
+	{
+		flat->SetupLights(this, flat->sector->lighthead, lightdata, flat->sector->PortalGroup);
+	}
+	gl_RenderState.ApplyLightIndex(flat->dynlightindex);
 	if (iboindex >= 0)
 	{
 		if (vcount > 0 && !ClipLineShouldBeActive())
@@ -173,7 +170,7 @@ void FDrawInfo::DrawSubsectors(GLFlat *flat, int pass, bool processlights, bool
 
 		while (node)
 		{
-			if (processlights) gl_RenderState.ApplyLightIndex(node->lightindex);
+			gl_RenderState.ApplyLightIndex(node->lightindex);
 			DrawSubsector(flat, node->sub);
 			node = node->next;
 		}
@@ -187,10 +184,11 @@ void FDrawInfo::DrawSubsectors(GLFlat *flat, int pass, bool processlights, bool
 //
 //==========================================================================
 
-void FDrawInfo::DrawSkyboxSector(GLFlat *flat, int pass, bool processlights)
+void FDrawInfo::DrawSkyboxSector(GLFlat *flat, int pass)
 {
 	FQuadDrawer qd;
 	flat->CreateSkyboxVertices(qd.Pointer());
+	gl_RenderState.ApplyLightIndex(flat->dynlightindex);
 	qd.Render(GL_TRIANGLE_FAN);
 
 	flatvertices += 4;
@@ -208,7 +206,6 @@ void FDrawInfo::DrawFlat(GLFlat *flat, int pass, bool trans)	// trans only has m
 	int rel = getExtraLight();
 
 	auto &plane = flat->plane;
-    auto processLights = level.HasDynamicLights && !isFullbrightScene();
 	gl_RenderState.SetNormal(plane.plane.Normal().X, plane.plane.Normal().Z, plane.plane.Normal().Y);
 
 	switch (pass)
@@ -222,13 +219,13 @@ void FDrawInfo::DrawFlat(GLFlat *flat, int pass, bool trans)	// trans only has m
 		{
 			gl_RenderState.SetMaterial(flat->gltexture, CLAMP_NONE, 0, -1, false);
 			gl_RenderState.SetPlaneTextureRotation(&plane, flat->gltexture);
-			DrawSubsectors(flat, pass, processLights, false);
+			DrawSubsectors(flat, pass, false);
 			gl_RenderState.EnableTextureMatrix(false);
 		}
 		else
 		{
 			gl_RenderState.SetMaterial(flat->gltexture, CLAMP_XY, 0, -1, false);
-			DrawSkyboxSector(flat, pass, processLights);
+			DrawSkyboxSector(flat, pass);
 		}
 		gl_RenderState.SetObjectColor(0xffffffff);
 		break;
@@ -243,7 +240,7 @@ void FDrawInfo::DrawFlat(GLFlat *flat, int pass, bool trans)	// trans only has m
 		{
 			gl_RenderState.AlphaFunc(GL_GEQUAL, 0.f);
 			gl_RenderState.EnableTexture(false);
-			DrawSubsectors(flat, pass, false, true);
+			DrawSubsectors(flat, pass, true);
 			gl_RenderState.EnableTexture(true);
 		}
 		else 
@@ -252,7 +249,7 @@ void FDrawInfo::DrawFlat(GLFlat *flat, int pass, bool trans)	// trans only has m
 			else gl_RenderState.AlphaFunc(GL_GEQUAL, 0.f);
 			gl_RenderState.SetMaterial(flat->gltexture, CLAMP_NONE, 0, -1, false);
 			gl_RenderState.SetPlaneTextureRotation(&plane, flat->gltexture);
-			DrawSubsectors(flat, pass, processLights && (gl.lightmethod == LM_DIRECT || flat->dynlightindex > -1), true);
+			DrawSubsectors(flat, pass, true);
 			gl_RenderState.EnableTextureMatrix(false);
 		}
 		if (flat->renderstyle==STYLE_Add) gl_RenderState.BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);