diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index cbc5d3451..5164e0676 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -120,6 +120,8 @@ void GLFlat::SetupSubsectorLights(int pass, subsector_t * sub, int *dli)
 {
 	Plane p;
 
+	if (renderstyle == STYLE_Add) return;	// no lights on additively blended surfaces.
+
 	if (dli != NULL && *dli != -1)
 	{
 		gl_RenderState.ApplyLightIndex(GLRenderer->mLights->GetIndex(*dli));
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index a7cd23d42..20d170977 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -73,6 +73,8 @@ FDynLightData lightdata;
 
 void GLWall::SetupLights()
 {
+	if (RenderStyle == STYLE_Add) return;	// no lights on additively blended surfaces.
+
 	// check for wall types which cannot have dynamic lights on them (portal types never get here so they don't need to be checked.)
 	switch (type)
 	{