diff --git a/src/r_segs.c b/src/r_segs.c
index ccf5b1eea..d19aebd1c 100644
--- a/src/r_segs.c
+++ b/src/r_segs.c
@@ -2313,7 +2313,7 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 				{
 					if (!(rover->fofflags & FOF_RENDERSIDES) || !(rover->fofflags & FOF_EXISTS))
 						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;
 
 					if (rover->norender == leveltime)
@@ -2371,7 +2371,7 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 				{
 					if (!(rover->fofflags & FOF_RENDERSIDES) || !(rover->fofflags & FOF_EXISTS))
 						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;
 
 					if (rover->norender == leveltime)
@@ -2431,7 +2431,7 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 				{
 					if (!(rover->fofflags & FOF_RENDERSIDES) || !(rover->fofflags & FOF_EXISTS))
 						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;
 					if (rover->norender == leveltime)
 						continue;
@@ -2453,7 +2453,7 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 				{
 					if (!(rover->fofflags & FOF_RENDERSIDES) || !(rover->fofflags & FOF_EXISTS))
 						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;
 					if (rover->norender == leveltime)
 						continue;
@@ -2775,7 +2775,7 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 
 					if ((roverleft>>4 <= worldhigh || roverright>>4 <= worldhighslope) &&
 					    (roverleft>>4 >= worldlow || roverright>>4 >= worldlowslope) &&
-					    ((viewz < planevistest && (rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
+					    ((viewz < planevistest && (udmf && rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
 					     (viewz > planevistest && (rover->fofflags & FOF_BOTHPLANES || rover->fofflags & FOF_INVERTPLANES))))
 					{
 						//ffloor[i].slope = *rover->b_slope;
@@ -2798,7 +2798,7 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 
 					if ((roverleft>>4 <= worldhigh || roverright>>4 <= worldhighslope) &&
 					    (roverleft>>4 >= worldlow || roverright>>4 >= worldlowslope) &&
-					    ((viewz > planevistest && (rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
+					    ((viewz > planevistest && (udmf && rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
 					     (viewz < planevistest && (rover->fofflags & FOF_BOTHPLANES || rover->fofflags & FOF_INVERTPLANES))))
 					{
 						//ffloor[i].slope = *rover->t_slope;
@@ -2832,7 +2832,7 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 
 					if ((roverleft>>4 <= worldhigh || roverright>>4 <= worldhighslope) &&
 					    (roverleft>>4 >= worldlow || roverright>>4 >= worldlowslope) &&
-					    ((viewz < planevistest && (rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
+					    ((viewz < planevistest && (udmf && rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
 					     (viewz > planevistest && (rover->fofflags & FOF_BOTHPLANES || rover->fofflags & FOF_INVERTPLANES))))
 					{
 						//ffloor[i].slope = *rover->b_slope;
@@ -2855,7 +2855,7 @@ void R_StoreWallRange(INT32 start, INT32 stop)
 
 					if ((roverleft>>4 <= worldhigh || roverright>>4 <= worldhighslope) &&
 					    (roverleft>>4 >= worldlow || roverright>>4 >= worldlowslope) &&
-					    ((viewz > planevistest && (rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
+					    ((viewz > planevistest && (udmf && rover->fofflags & FOF_BOTHPLANES || !(rover->fofflags & FOF_INVERTPLANES))) ||
 					     (viewz < planevistest && (rover->fofflags & FOF_BOTHPLANES || rover->fofflags & FOF_INVERTPLANES))))
 					{
 						//ffloor[i].slope = *rover->t_slope;