diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index e399037fa..159a8e16a 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -57,6 +57,7 @@ void FDrawInfo::SetupSubsectorLights(GLFlat *flat, int pass, subsector_t * sub,
 {
 	if (dli != NULL && *dli != -1)
 	{
+		if (flat->renderstyle == STYLE_Add && !level.lightadditivesurfaces) return;	// no lights on additively blended surfaces.
 		gl_RenderState.ApplyLightIndex(GLRenderer->mLights->GetIndex(*dli));
 		(*dli)++;
 		return;
@@ -85,6 +86,7 @@ void FDrawInfo::SetupSectorLights(GLFlat *flat, int pass, int *dli)
 {
 	if (dli != NULL && *dli != -1)
 	{
+		if (flat->renderstyle == STYLE_Add && !level.lightadditivesurfaces) return;	// no lights on additively blended surfaces.
 		gl_RenderState.ApplyLightIndex(GLRenderer->mLights->GetIndex(*dli));
 		(*dli)++;
 		return;
diff --git a/src/hwrenderer/scene/hw_flats.cpp b/src/hwrenderer/scene/hw_flats.cpp
index 91cb8027e..0c3ec07e4 100644
--- a/src/hwrenderer/scene/hw_flats.cpp
+++ b/src/hwrenderer/scene/hw_flats.cpp
@@ -139,9 +139,9 @@ bool GLFlat::SetupLights(int pass, FLightNode * node, FDynLightData &lightdata,
 {
 	Plane p;
 
+	lightdata.Clear();
 	if (renderstyle == STYLE_Add && !level.lightadditivesurfaces) return false;	// no lights on additively blended surfaces.
 
-	lightdata.Clear();
 	while (node)
 	{
 		ADynamicLight * light = node->lightsource;