diff --git a/source/build/include/build.h b/source/build/include/build.h
index 2c2989e3c..71744b01a 100644
--- a/source/build/include/build.h
+++ b/source/build/include/build.h
@@ -158,6 +158,21 @@ inline sectortype* spritetype::sector() const
     return &::sector[sectnum];
 }
 
+inline sectortype* walltype::nextSector() const
+{
+    return &::sector[nextsector];
+}
+
+inline walltype* walltype::nextWall() const
+{
+    return &::wall[nextwall];
+}
+
+inline walltype* sectortype::firstWall() const
+{
+    return &wall[wallptr];
+}
+
 
 extern sectortype sectorbackup[MAXSECTORS];
 extern walltype wallbackup[MAXWALLS];
diff --git a/source/build/include/buildtypes.h b/source/build/include/buildtypes.h
index 354c1a63d..3cd8b9de9 100644
--- a/source/build/include/buildtypes.h
+++ b/source/build/include/buildtypes.h
@@ -51,6 +51,7 @@ enum
 
 
 //40 bytes
+struct walltype;
 struct sectortype
 {
     int16_t wallptr, wallnum;
@@ -87,6 +88,7 @@ struct sectortype
     void addfloorypan(float add) { floorypan_ = fmodf(floorypan_ + add + 512, 256); } // +512 is for handling negative offsets
     void addceilingxpan(float add) { ceilingxpan_ = fmodf(ceilingxpan_ + add + 512, 256); } // +512 is for handling negative offsets
     void addceilingypan(float add) { ceilingypan_ = fmodf(ceilingypan_ + add + 512, 256); } // +512 is for handling negative offsets
+    walltype *firstWall() const;
 };
 
 //cstat:
@@ -134,6 +136,9 @@ struct walltype
     void setypan(float add) { ypan_ = fmodf(add + 512, 256); } // +512 is for handling negative offsets
     void addxpan(float add) { xpan_ = fmodf(xpan_ + add + 512, 256); } // +512 is for handling negative offsets
     void addypan(float add) { ypan_ = fmodf(ypan_ + add + 512, 256); } // +512 is for handling negative offsets
+    sectortype* nextSector() const;
+    walltype* nextWall() const;
+    bool twoSided() const { return nextsector >= 0; }
 
 #if 0
     // make sure we do not accidentally copy this
diff --git a/source/games/duke/src/actors_d.cpp b/source/games/duke/src/actors_d.cpp
index 5b2ff2bf6..a1b40564a 100644
--- a/source/games/duke/src/actors_d.cpp
+++ b/source/games/duke/src/actors_d.cpp
@@ -3773,7 +3773,7 @@ void moveeffectors_d(void)   //STATNUM 3
 		auto sc = act->getSector();
 		if (sc->wallnum != 4) continue;
 		auto wal = &wall[sc->wallptr + 2];
-		alignflorslope(act->s->sectnum, wal->x, wal->y, sector[wal->nextsector].floorz);
+		alignflorslope(act->s->sectnum, wal->x, wal->y, wal->nextSector()->floorz);
 	}
 }
 
diff --git a/source/games/duke/src/actors_r.cpp b/source/games/duke/src/actors_r.cpp
index a0eac46f3..5c4c36566 100644
--- a/source/games/duke/src/actors_r.cpp
+++ b/source/games/duke/src/actors_r.cpp
@@ -3653,7 +3653,7 @@ void moveeffectors_r(void)   //STATNUM 3
 		auto sc = act->getSector();
 		if (sc->wallnum != 4) continue;
 		auto wal = &wall[sc->wallptr + 2];
-		alignflorslope(act->s->sectnum, wal->x, wal->y, sector[wal->nextsector].floorz);
+		alignflorslope(act->s->sectnum, wal->x, wal->y, wal->nextSector()->floorz);
 	}
 }
 
diff --git a/source/games/duke/src/player_d.cpp b/source/games/duke/src/player_d.cpp
index 979fd3746..e84c65b2d 100644
--- a/source/games/duke/src/player_d.cpp
+++ b/source/games/duke/src/player_d.cpp
@@ -492,7 +492,7 @@ static void shootweapon(DDukeActor *actor, int p, int sx, int sy, int sz, int sa
 
 			if (hitsect >= 0 && sector[hitsect].lotag == 0)
 				if (wal->overpicnum != BIGFORCE)
-					if ((wal->nextsector >= 0 && sector[wal->nextsector].lotag == 0) ||
+					if ((wal->nextsector >= 0 && wal->nextSector()->lotag == 0) ||
 						(wal->nextsector == -1 && sector[hitsect].lotag == 0))
 						if ((wal->cstat & 16) == 0)
 						{
@@ -524,7 +524,7 @@ static void shootweapon(DDukeActor *actor, int p, int sx, int sy, int sz, int sa
 
 			if (wal->cstat & 2)
 				if (wal->nextsector >= 0)
-					if (hitz >= (sector[wal->nextsector].floorz))
+					if (hitz >= (wal->nextSector()->floorz))
 						hitwall = wal->nextwall;
 
 			fi.checkhitwall(spark, hitwall, hitx, hity, hitz, SHOTSPARK1);
diff --git a/source/games/duke/src/player_r.cpp b/source/games/duke/src/player_r.cpp
index b80ea5e26..26d4af874 100644
--- a/source/games/duke/src/player_r.cpp
+++ b/source/games/duke/src/player_r.cpp
@@ -392,7 +392,7 @@ static void shootweapon(DDukeActor* actor, int p, int sx, int sy, int sz, int sa
 
 			if (hitsect >= 0 && sector[hitsect].lotag == 0)
 				if (wal->overpicnum != BIGFORCE)
-					if ((wal->nextsector >= 0 && sector[wal->nextsector].lotag == 0) ||
+					if ((wal->nextsector >= 0 && wal->nextSector()->lotag == 0) ||
 						(wal->nextsector == -1 && sector[hitsect].lotag == 0))
 						if ((wal->cstat & 16) == 0)
 						{
@@ -424,7 +424,7 @@ static void shootweapon(DDukeActor* actor, int p, int sx, int sy, int sz, int sa
 
 			if (wal->cstat & 2)
 				if (wal->nextsector >= 0)
-					if (hitz >= (sector[wal->nextsector].floorz))
+					if (hitz >= (wal->nextSector()->floorz))
 						hitwall = wal->nextwall;
 
 			fi.checkhitwall(spark, hitwall, hitx, hity, hitz, SHOTSPARK1);
diff --git a/source/games/duke/src/sectors_d.cpp b/source/games/duke/src/sectors_d.cpp
index 627f4e055..7d768e1c5 100644
--- a/source/games/duke/src/sectors_d.cpp
+++ b/source/games/duke/src/sectors_d.cpp
@@ -667,8 +667,8 @@ void checkhitwall_d(DDukeActor* spr, int dawallnum, int x, int y, int z, int atw
 	}
 
 	if (((wal->cstat & 16) || wal->overpicnum == BIGFORCE) && wal->nextsector >= 0)
-		if (sector[wal->nextsector].floorz > z)
-			if (sector[wal->nextsector].floorz - sector[wal->nextsector].ceilingz)
+		if (wal->nextSector()->floorz > z)
+			if (wal->nextSector()->floorz - wal->nextSector()->ceilingz)
 				switch (wal->overpicnum)
 				{
 				case W_FORCEFIELD:
diff --git a/source/games/duke/src/sectors_r.cpp b/source/games/duke/src/sectors_r.cpp
index 49fafa66d..0ae2739b6 100644
--- a/source/games/duke/src/sectors_r.cpp
+++ b/source/games/duke/src/sectors_r.cpp
@@ -1006,8 +1006,8 @@ void checkhitwall_r(DDukeActor* spr, int dawallnum, int x, int y, int z, int atw
 	}
 
 	if (((wal->cstat & 16) || wal->overpicnum == BIGFORCE) && wal->nextsector >= 0)
-		if (sector[wal->nextsector].floorz > z)
-			if (sector[wal->nextsector].floorz - sector[wal->nextsector].ceilingz)
+		if (wal->nextSector()->floorz > z)
+			if (wal->nextSector()->floorz - wal->nextSector()->ceilingz)
 				switch (wal->overpicnum)
 				{
 				case FANSPRITE: