diff --git a/src/doomdata.h b/src/doomdata.h
index 4c5bdefaf..45cbb2557 100644
--- a/src/doomdata.h
+++ b/src/doomdata.h
@@ -62,6 +62,10 @@ enum
 #define MTF_AMBUSH 8
 
 // Do not use bit five or after, as they are used for object z-offsets.
+// Unless it's exclusive to UDMF.
+
+// Flag to use Z as absolute spawn height, ignoring the floor and ceiling.
+#define MTF_ABSOLUTEZ 16
 
 #if defined(_MSC_VER)
 #pragma pack(1)
diff --git a/src/p_mobj.c b/src/p_mobj.c
index a04351ae7..0622ff601 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -11812,7 +11812,7 @@ void P_MovePlayerToStarpost(INT32 playernum)
 mapthing_t *huntemeralds[MAXHUNTEMERALDS];
 INT32 numhuntemeralds;
 
-fixed_t P_GetMobjSpawnHeight(const mobjtype_t mobjtype, const fixed_t x, const fixed_t y, const fixed_t dz, const fixed_t offset, const boolean flip, const fixed_t scale)
+fixed_t P_GetMobjSpawnHeight(const mobjtype_t mobjtype, const fixed_t x, const fixed_t y, const fixed_t dz, const fixed_t offset, const boolean flip, const fixed_t scale, const boolean absolutez)
 {
 	const subsector_t *ss = R_PointInSubsector(x, y);
 
@@ -11822,9 +11822,9 @@ fixed_t P_GetMobjSpawnHeight(const mobjtype_t mobjtype, const fixed_t x, const f
 
 	// Establish height.
 	if (flip)
-		return P_GetSectorCeilingZAt(ss->sector, x, y) - dz - FixedMul(scale, offset + mobjinfo[mobjtype].height);
+		return (absolutez ? dz : P_GetSectorCeilingZAt(ss->sector, x, y) - dz) - FixedMul(scale, offset + mobjinfo[mobjtype].height);
 	else
-		return P_GetSectorFloorZAt(ss->sector, x, y) + dz + FixedMul(scale, offset);
+		return (absolutez ? dz : P_GetSectorFloorZAt(ss->sector, x, y) + dz) + FixedMul(scale, offset);
 }
 
 fixed_t P_GetMapThingSpawnHeight(const mobjtype_t mobjtype, const mapthing_t* mthing, const fixed_t x, const fixed_t y)
@@ -11832,6 +11832,7 @@ fixed_t P_GetMapThingSpawnHeight(const mobjtype_t mobjtype, const mapthing_t* mt
 	fixed_t dz = mthing->z << FRACBITS; // Base offset from the floor.
 	fixed_t offset = 0; // Specific scaling object offset.
 	boolean flip = (!!(mobjinfo[mobjtype].flags & MF_SPAWNCEILING) ^ !!(mthing->options & MTF_OBJECTFLIP));
+	boolean absolutez = !!(mthing->options & MTF_ABSOLUTEZ);
 
 	switch (mobjtype)
 	{
@@ -11887,7 +11888,7 @@ fixed_t P_GetMapThingSpawnHeight(const mobjtype_t mobjtype, const mapthing_t* mt
 			offset += mthing->args[0] ? 0 : 24*FRACUNIT;
 	}
 
-	if (!(dz + offset)) // Snap to the surfaces when there's no offset set.
+	if (!(dz + offset) && !absolutez) // Snap to the surfaces when there's no offset set.
 	{
 		if (flip)
 			return ONCEILINGZ;
@@ -11895,7 +11896,7 @@ fixed_t P_GetMapThingSpawnHeight(const mobjtype_t mobjtype, const mapthing_t* mt
 			return ONFLOORZ;
 	}
 
-	return P_GetMobjSpawnHeight(mobjtype, x, y, dz, offset, flip, mthing->scale);
+	return P_GetMobjSpawnHeight(mobjtype, x, y, dz, offset, flip, mthing->scale, absolutez);
 }
 
 static boolean P_SpawnNonMobjMapThing(mapthing_t *mthing)
@@ -13389,7 +13390,7 @@ void P_SpawnHoop(mapthing_t *mthing)
 	vector4_t v, res;
 	fixed_t x = mthing->x << FRACBITS;
 	fixed_t y = mthing->y << FRACBITS;
-	fixed_t z = P_GetMobjSpawnHeight(MT_HOOP, x, y, mthing->z << FRACBITS, 0, false, mthing->scale);
+	fixed_t z = P_GetMobjSpawnHeight(MT_HOOP, x, y, mthing->z << FRACBITS, 0, false, mthing->scale, !!(mthing->options & MTF_ABSOLUTEZ));
 
 	hoopcenter = P_SpawnMobj(x, y, z, MT_HOOPCENTER);
 	hoopcenter->spawnpoint = mthing;
@@ -13516,7 +13517,7 @@ static void P_SpawnItemRow(mapthing_t *mthing, mobjtype_t *itemtypes, UINT8 numi
 			itemtypes[r] = P_GetMobjtypeSubstitute(&dummything, itemtypes[r]);
 		}
 	}
-	z = P_GetMobjSpawnHeight(itemtypes[0], x, y, z, 0, mthing->options & MTF_OBJECTFLIP, mthing->scale);
+	z = P_GetMobjSpawnHeight(itemtypes[0], x, y, z, 0, mthing->options & MTF_OBJECTFLIP, mthing->scale, !!(mthing->options & MTF_ABSOLUTEZ));
 
 	for (r = 0; r < numitems; r++)
 	{
@@ -13575,7 +13576,7 @@ static void P_SpawnItemCircle(mapthing_t *mthing, mobjtype_t *itemtypes, UINT8 n
 			itemtypes[i] = P_GetMobjtypeSubstitute(&dummything, itemtypes[i]);
 		}
 	}
-	z = P_GetMobjSpawnHeight(itemtypes[0], x, y, z, 0, false, mthing->scale);
+	z = P_GetMobjSpawnHeight(itemtypes[0], x, y, z, 0, false, mthing->scale, !!(mthing->options & MTF_ABSOLUTEZ));
 
 	for (i = 0; i < numitems; i++)
 	{
diff --git a/src/p_mobj.h b/src/p_mobj.h
index 6717c4add..d7d660078 100644
--- a/src/p_mobj.h
+++ b/src/p_mobj.h
@@ -489,7 +489,7 @@ void P_MovePlayerToSpawn(INT32 playernum, mapthing_t *mthing);
 void P_MovePlayerToStarpost(INT32 playernum);
 void P_AfterPlayerSpawn(INT32 playernum);
 
-fixed_t P_GetMobjSpawnHeight(const mobjtype_t mobjtype, const fixed_t x, const fixed_t y, const fixed_t dz, const fixed_t offset, const boolean flip, const fixed_t scale);
+fixed_t P_GetMobjSpawnHeight(const mobjtype_t mobjtype, const fixed_t x, const fixed_t y, const fixed_t dz, const fixed_t offset, const boolean flip, const fixed_t scale, const boolean absolutez);
 fixed_t P_GetMapThingSpawnHeight(const mobjtype_t mobjtype, const mapthing_t* mthing, const fixed_t x, const fixed_t y);
 
 mobj_t *P_SpawnMapThing(mapthing_t *mthing);
diff --git a/src/p_setup.c b/src/p_setup.c
index 74645e877..167e1baac 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -1916,6 +1916,8 @@ static void ParseTextmapThingParameter(UINT32 i, const char *param, const char *
 	// Flags
 	else if (fastcmp(param, "flip") && fastcmp("true", val))
 		mapthings[i].options |= MTF_OBJECTFLIP;
+	else if (fastcmp(param, "absolutez") && fastcmp("true", val))
+		mapthings[i].options |= MTF_ABSOLUTEZ;
 
 	else if (fastncmp(param, "stringarg", 9) && strlen(param) > 9)
 	{