diff --git a/src/gl/scene/gl_wall.h b/src/gl/scene/gl_wall.h
index e44155aa6..00459644c 100644
--- a/src/gl/scene/gl_wall.h
+++ b/src/gl/scene/gl_wall.h
@@ -118,7 +118,7 @@ public:
 	
 	fixed_t viewdistance;
 
-	BYTE lightlevel;
+	int lightlevel;
 	BYTE type;
 	BYTE flags;
 	short rellight;
diff --git a/src/gl/scene/gl_walls.cpp b/src/gl/scene/gl_walls.cpp
index 40c18baa9..e7265c1a1 100644
--- a/src/gl/scene/gl_walls.cpp
+++ b/src/gl/scene/gl_walls.cpp
@@ -1098,7 +1098,7 @@ void GLWall::BuildFFBlock(seg_t * seg, F3DFloor * rover,
 	float to;
 	lightlist_t * light;
 	bool translucent;
-	byte savelight=lightlevel;
+	int savelight=lightlevel;
 	FColormap savecolor=Colormap;
 	float ul;
 	float texlength;
@@ -1108,12 +1108,12 @@ void GLWall::BuildFFBlock(seg_t * seg, F3DFloor * rover,
 	{
 		if (!gl_fixedcolormap)
 		{
-			// this may not yet be done!
+			// this may not yet be done
 			light=P_GetPlaneLight(rover->target, rover->top.plane,true);
 			Colormap.Clear();
 			Colormap.LightColor=(light->extra_colormap)->Fade;
-			// the fog plane defines the light level, not the front sector!
-			lightlevel=*light->p_lightlevel;
+			// the fog plane defines the light level, not the front sector
+			lightlevel = gl_ClampLight(*light->p_lightlevel);
 			gltexture=NULL;
 			type=RENDERWALL_FFBLOCK;
 		}
@@ -1520,7 +1520,7 @@ void GLWall::Process(seg_t *seg, sector_t * frontsector, sector_t * backsector)
 
 	int rel = 0;
 	int orglightlevel = gl_ClampLight(frontsector->lightlevel);
-	lightlevel = seg->sidedef->GetLightLevel(!!(flags&GLWF_FOGGY), orglightlevel, false, &rel);
+	lightlevel = gl_ClampLight(seg->sidedef->GetLightLevel(!!(flags&GLWF_FOGGY), orglightlevel, false, &rel));
 	if (orglightlevel >= 253)			// with the software renderer fake contrast won't be visible above this.
 	{
 		rellight = 0;