diff --git a/src/hardware/hw_main.c b/src/hardware/hw_main.c
index 10ab1804d..b58f7f96d 100644
--- a/src/hardware/hw_main.c
+++ b/src/hardware/hw_main.c
@@ -1761,7 +1761,7 @@ static void HWR_ProcessSeg(void) // Sort of like GLWall::Process in GZDoom
 
 				if (!(rover->fofflags & FOF_EXISTS) || !(rover->fofflags & FOF_RENDERSIDES))
 					continue;
-				if (!(rover->fofflags & FOF_ALLSIDES) && rover->fofflags & FOF_INVERTSIDES)
+				if (udmf && !(rover->fofflags & FOF_ALLSIDES) && rover->fofflags & FOF_INVERTSIDES || !udmf && rover->fofflags & FOF_INVERTSIDES)
 					continue;
 
 				SLOPEPARAMS(*rover->t_slope, high1, highslope1, *rover->topheight)
@@ -1921,7 +1921,7 @@ static void HWR_ProcessSeg(void) // Sort of like GLWall::Process in GZDoom
 
 				if (!(rover->fofflags & FOF_EXISTS) || !(rover->fofflags & FOF_RENDERSIDES))
 					continue;
-				if (!(rover->fofflags & FOF_ALLSIDES || rover->fofflags & FOF_INVERTSIDES))
+				if (udmf && !(rover->fofflags & FOF_ALLSIDES) && rover->fofflags & FOF_INVERTSIDES || !udmf && rover->fofflags & FOF_INVERTSIDES)
 					continue;
 
 				SLOPEPARAMS(*rover->t_slope, high1, highslope1, *rover->topheight)
@@ -2851,7 +2851,7 @@ static void HWR_Subsector(size_t num)
 
 			if (centerHeight <= locCeilingHeight &&
 			    centerHeight >= locFloorHeight &&
-			    ((dup_viewz < cullHeight && (rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
+			    ((dup_viewz < cullHeight && (udmf && rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
 			     (dup_viewz > cullHeight && (rover->fofflags & FOF_BOTHPLANES || rover->fofflags & FOF_INVERTPLANES))))
 			{
 				if (rover->fofflags & FOF_FOG)
@@ -2899,7 +2899,7 @@ static void HWR_Subsector(size_t num)
 
 			if (centerHeight >= locFloorHeight &&
 			    centerHeight <= locCeilingHeight &&
-			    ((dup_viewz > cullHeight && (rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
+			    ((dup_viewz > cullHeight && (udmf && rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
 			     (dup_viewz < cullHeight && (rover->fofflags & FOF_BOTHPLANES || rover->fofflags & FOF_INVERTPLANES))))
 			{
 				if (rover->fofflags & FOF_FOG)