diff --git a/src/swrenderer/plane/r_fogboundary.cpp b/src/swrenderer/plane/r_fogboundary.cpp
index 5244b937f..3dff9fa60 100644
--- a/src/swrenderer/plane/r_fogboundary.cpp
+++ b/src/swrenderer/plane/r_fogboundary.cpp
@@ -42,7 +42,7 @@ namespace swrenderer
 		short spanend[MAXHEIGHT];
 	}
 
-	void R_DrawFogBoundary(int x1, int x2, short *uclip, short *dclip)
+	void R_DrawFogBoundary(int x1, int x2, short *uclip, short *dclip, int wallshade)
 	{
 		// This is essentially the same as R_MapVisPlane but with an extra step
 		// to create new horizontal spans whenever the light changes enough that
diff --git a/src/swrenderer/plane/r_fogboundary.h b/src/swrenderer/plane/r_fogboundary.h
index 0e9af3322..f334e916b 100644
--- a/src/swrenderer/plane/r_fogboundary.h
+++ b/src/swrenderer/plane/r_fogboundary.h
@@ -5,6 +5,6 @@
 
 namespace swrenderer
 {
-	void R_DrawFogBoundary(int x1, int x2, short *uclip, short *dclip);
+	void R_DrawFogBoundary(int x1, int x2, short *uclip, short *dclip, int wallshade);
 	void R_DrawFogBoundarySection(int y, int y2, int x1);
 }
diff --git a/src/swrenderer/scene/r_segs.cpp b/src/swrenderer/scene/r_segs.cpp
index 5a8fb2982..0ebfaa084 100644
--- a/src/swrenderer/scene/r_segs.cpp
+++ b/src/swrenderer/scene/r_segs.cpp
@@ -272,7 +272,7 @@ void R_RenderMaskedSegRange (drawseg_t *ds, int x1, int x2)
 	// [RH] Draw fog partition
 	if (ds->bFogBoundary)
 	{
-		R_DrawFogBoundary (x1, x2, mceilingclip, mfloorclip);
+		R_DrawFogBoundary (x1, x2, mceilingclip, mfloorclip, wallshade);
 		if (ds->maskedtexturecol == -1)
 		{
 			goto clearfog;