diff --git a/source/games/duke/src/actors.cpp b/source/games/duke/src/actors.cpp
index 3e2384a3e..445873639 100644
--- a/source/games/duke/src/actors.cpp
+++ b/source/games/duke/src/actors.cpp
@@ -469,7 +469,7 @@ void moveplayers(void)
 					act->SetHitOwner(act);
 
 					if (ud.god == 0)
-						if (fi.ceilingspace(spri->sectnum) || fi.floorspace(spri->sectnum))
+						if (fi.ceilingspace(spri->sector()) || fi.floorspace(spri->sector()))
 							quickkill(p);
 				}
 				else
@@ -5015,11 +5015,11 @@ void makeitfall(DDukeActor* actor)
 	auto s = actor->s;
 	int c;
 
-	if( fi.floorspace(s->sectnum) )
+	if( fi.floorspace(s->sector()) )
 		c = 0;
 	else
 	{
-		if( fi.ceilingspace(s->sectnum) || s->sector()->lotag == ST_2_UNDERWATER)
+		if( fi.ceilingspace(s->sector()) || s->sector()->lotag == ST_2_UNDERWATER)
 			c = gs.gravity/6;
 		else c = gs.gravity;
 	}
@@ -5266,11 +5266,11 @@ void fall_common(DDukeActor *actor, int playernum, int JIBS6, int DRONE, int BLO
 		int c;
 
 		int sphit = fallspecial? fallspecial(actor, playernum) : 0;
-		if (fi.floorspace(s->sectnum))
+		if (fi.floorspace(s->sector()))
 			c = 0;
 		else
 		{
-			if (fi.ceilingspace(s->sectnum) || s->sector()->lotag == 2)
+			if (fi.ceilingspace(s->sector()) || s->sector()->lotag == 2)
 				c = gs.gravity / 6;
 			else c = gs.gravity;
 		}
diff --git a/source/games/duke/src/actors_d.cpp b/source/games/duke/src/actors_d.cpp
index c158cd7da..61fc966b5 100644
--- a/source/games/duke/src/actors_d.cpp
+++ b/source/games/duke/src/actors_d.cpp
@@ -104,11 +104,11 @@ void SerializeActorGlobals(FSerializer& arc)
 //
 //---------------------------------------------------------------------------
 
-bool ceilingspace_d(int sectnum)
+bool ceilingspace_d(sectortype* sectp)
 {
-	if( (sector[sectnum].ceilingstat&1) && sector[sectnum].ceilingpal == 0 )
+	if( (sectp->ceilingstat&1) && sectp->ceilingpal == 0 )
 	{
-		switch(sector[sectnum].ceilingpicnum)
+		switch(sectp->ceilingpicnum)
 		{
 			case MOONSKY1:
 			case BIGORBIT1:
@@ -124,11 +124,11 @@ bool ceilingspace_d(int sectnum)
 //
 //---------------------------------------------------------------------------
 
-bool floorspace_d(int sectnum)
+bool floorspace_d(sectortype* sectp)
 {
-	if( (sector[sectnum].floorstat&1) && sector[sectnum].ceilingpal == 0 )
+	if( (sectp->floorstat&1) && sectp->ceilingpal == 0 )
 	{
-		switch(sector[sectnum].floorpicnum)
+		switch(sectp->floorpicnum)
 		{
 			case MOONSKY1:
 			case BIGORBIT1:
@@ -1002,10 +1002,10 @@ void movefallers_d(void)
 					ssp(act, CLIPMASK0);
 				}
 
-				if (fi.floorspace(s->sectnum)) x = 0;
+				if (fi.floorspace(s->sector())) x = 0;
 				else
 				{
-					if (fi.ceilingspace(s->sectnum))
+					if (fi.ceilingspace(s->sector()))
 						x = gs.gravity / 6;
 					else
 						x = gs.gravity;
diff --git a/source/games/duke/src/actors_r.cpp b/source/games/duke/src/actors_r.cpp
index c6cb4a4ca..71a37f562 100644
--- a/source/games/duke/src/actors_r.cpp
+++ b/source/games/duke/src/actors_r.cpp
@@ -51,11 +51,11 @@ void resetlanepics(void);
 //
 //---------------------------------------------------------------------------
 
-bool ceilingspace_r(int sectnum)
+bool ceilingspace_r(sectortype* sectp)
 {
-	if( (sector[sectnum].ceilingstat&1) && sector[sectnum].ceilingpal == 0 )
+	if( (sectp->ceilingstat&1) && sectp->ceilingpal == 0 )
 	{
-		switch(sector[sectnum].ceilingpicnum)
+		switch(sectp->ceilingpicnum)
 		{
 			case MOONSKY1:
 			case BIGORBIT1:
@@ -65,17 +65,18 @@ bool ceilingspace_r(int sectnum)
 	return 0;
 }
 
+
 //---------------------------------------------------------------------------
 //
 // 
 //
 //---------------------------------------------------------------------------
 
-bool floorspace_r(int sectnum)
+bool floorspace_r(sectortype* sectp)
 {
-	if( (sector[sectnum].floorstat&1) && sector[sectnum].ceilingpal == 0 )
+	if( (sectp->floorstat&1) && sectp->ceilingpal == 0 )
 	{
-		switch(sector[sectnum].floorpicnum)
+		switch(sectp->floorpicnum)
 		{
 			case MOONSKY1:
 			case BIGORBIT1:
@@ -856,10 +857,10 @@ void movefallers_r(void)
 				}
 
 				int x;
-				if (fi.floorspace(s->sectnum)) x = 0;
+				if (fi.floorspace(s->sector())) x = 0;
 				else
 				{
-					if (fi.ceilingspace(s->sectnum))
+					if (fi.ceilingspace(s->sector()))
 						x = gs.gravity / 6;
 					else
 						x = gs.gravity;
diff --git a/source/games/duke/src/dispatch.cpp b/source/games/duke/src/dispatch.cpp
index 0a617c345..351e5ebc2 100644
--- a/source/games/duke/src/dispatch.cpp
+++ b/source/games/duke/src/dispatch.cpp
@@ -56,10 +56,10 @@ void checkhitsprite_r(DDukeActor* i, DDukeActor* sn);
 void checksectors_d(int snum);
 void checksectors_r(int snum);
 
-bool ceilingspace_d(int sectnum);
-bool ceilingspace_r(int sectnum);
-bool floorspace_d(int sectnum);
-bool floorspace_r(int sectnum);
+bool ceilingspace_d(sectortype*);
+bool ceilingspace_r(sectortype*);
+bool floorspace_d(sectortype*);
+bool floorspace_r(sectortype*);
 void addweapon_d(struct player_struct* p, int weapon);
 void addweapon_r(struct player_struct* p, int weapon);
 void hitradius_d(DDukeActor* i, int  r, int  hp1, int  hp2, int  hp3, int  hp4);
diff --git a/source/games/duke/src/duke3d.h b/source/games/duke/src/duke3d.h
index 8e8f4dfd2..fcdb53009 100644
--- a/source/games/duke/src/duke3d.h
+++ b/source/games/duke/src/duke3d.h
@@ -88,8 +88,8 @@ struct Dispatcher
 	void (*checkhitsprite)(DDukeActor* i, DDukeActor* sn);
 	void (*checksectors)(int low);
 
-	bool (*ceilingspace)(int sectnum);
-	bool (*floorspace)(int sectnum);
+	bool (*ceilingspace)(sectortype* sectp);
+	bool (*floorspace)(sectortype* sectp);
 	void (*addweapon)(struct player_struct *p, int weapon);
 	void (*hitradius)(DDukeActor* i, int  r, int  hp1, int  hp2, int  hp3, int  hp4);
 	void (*lotsofmoney)(DDukeActor *s, short n);
diff --git a/source/games/duke/src/gameexec.cpp b/source/games/duke/src/gameexec.cpp
index 939da3ecd..e93671908 100644
--- a/source/games/duke/src/gameexec.cpp
+++ b/source/games/duke/src/gameexec.cpp
@@ -2511,7 +2511,7 @@ int ParseState::parse(void)
 		}
 		break;
 	case concmd_ifinspace:
-		parseifelse(fi.ceilingspace(g_sp->sectnum));
+		parseifelse(fi.ceilingspace(g_sp->sector()));
 		break;
 
 	case concmd_spritepal:
@@ -2811,7 +2811,7 @@ int ParseState::parse(void)
 		insptr++;
 		break;
 	case concmd_ifinouterspace:
-		parseifelse( fi.floorspace(g_sp->sectnum));
+		parseifelse( fi.floorspace(g_sp->sector()));
 		break;
 	case concmd_ifnotmoving:
 		parseifelse( (g_ac->movflag&kHitTypeMask) > kHitSector );