diff --git a/src/p_map.c b/src/p_map.c
index e629db522..b5de9cb23 100644
--- a/src/p_map.c
+++ b/src/p_map.c
@@ -100,6 +100,9 @@ camera_t *mapcampointer;
 //
 static boolean P_TeleportMove(mobj_t *thing, fixed_t x, fixed_t y, fixed_t z)
 {
+	boolean startingonground = P_IsObjectOnGround(thing);
+	sector_t *oldsector = thing->subsector->sector;
+
 	numspechit = 0U;
 
 	// the move is ok,
@@ -129,6 +132,8 @@ static boolean P_TeleportMove(mobj_t *thing, fixed_t x, fixed_t y, fixed_t z)
 	thing->floorrover = g_tm.floorrover;
 	thing->ceilingrover = g_tm.ceilingrover;
 
+	P_CheckSectorTransitionalEffects(thing, oldsector, startingonground);
+
 	return true;
 }
 
@@ -2745,6 +2750,7 @@ boolean P_TryMove(mobj_t *thing, fixed_t x, fixed_t y, boolean allowdropoff, Try
 	fixed_t oldx = thing->x;
 	fixed_t oldy = thing->y;
 	fixed_t startingonground = P_IsObjectOnGround(thing);
+	sector_t *oldsector = thing->subsector->sector;
 
 	// Is the move OK?
 	if (increment_move(thing, x, y, allowdropoff, result) == false)
@@ -2847,6 +2853,8 @@ boolean P_TryMove(mobj_t *thing, fixed_t x, fixed_t y, boolean allowdropoff, Try
 
 	P_SetThingPosition(thing);
 
+	P_CheckSectorTransitionalEffects(thing, oldsector, startingonground);
+
 	// remove any duplicates that may be in spechitint
 	spechitint_removedups();
 
diff --git a/src/p_maputl.c b/src/p_maputl.c
index 9069026dd..95fc912f8 100644
--- a/src/p_maputl.c
+++ b/src/p_maputl.c
@@ -1236,7 +1236,6 @@ static void P_LinkToBlockMap(mobj_t *thing, mobj_t **bmap)
 void P_SetThingPosition(mobj_t *thing)
 {                                                      // link into subsector
 	subsector_t *ss;
-	sector_t *prevsec = NULL;
 	sector_t *oldsec = NULL;
 	fixed_t tfloorz, tceilz;
 
@@ -1249,11 +1248,6 @@ void P_SetThingPosition(mobj_t *thing)
 		oldsec = thing->subsector->sector;
 	}
 
-	if (thing->subsector)
-	{
-		prevsec = thing->subsector->sector;
-	}
-
 	ss = thing->subsector = R_PointInSubsector(thing->x, thing->y);
 
 	if (!(thing->flags & MF_NOSECTOR))
@@ -1310,12 +1304,6 @@ void P_SetThingPosition(mobj_t *thing)
 		else if (thing->z <= tfloorz)
 			thing->eflags |= MFE_JUSTSTEPPEDDOWN;
 	}
-
-	if (udmf && prevsec != thing->subsector->sector)
-	{
-		// Check for each time / once sector special actions
-		P_CheckMobjTouchingSectorActions(thing, false);
-	}
 }
 
 //
diff --git a/src/p_mobj.c b/src/p_mobj.c
index 0d1bab4a5..67df9b58b 100644
--- a/src/p_mobj.c
+++ b/src/p_mobj.c
@@ -2175,10 +2175,13 @@ boolean P_ZMovement(mobj_t *mo)
 {
 	fixed_t dist, delta;
 	boolean onground;
+	boolean wasonground;
 
 	I_Assert(mo != NULL);
 	I_Assert(!P_MobjWasRemoved(mo));
 
+	wasonground = P_IsObjectOnGround(mo);
+
 	// Intercept the stupid 'fall through 3dfloors' bug
 	if (mo->subsector->sector->ffloors)
 		P_AdjustMobjFloorZ_FFloors(mo, mo->subsector->sector, 0);
@@ -2604,6 +2607,8 @@ boolean P_ZMovement(mobj_t *mo)
 		}
 	}
 
+	P_CheckSectorTransitionalEffects(mo, mo->subsector->sector, wasonground);
+
 	return true;
 }
 
@@ -2697,6 +2702,7 @@ static boolean P_PlayerPolyObjectZMovement(mobj_t *mo)
 void P_PlayerZMovement(mobj_t *mo)
 {
 	boolean onground;
+	boolean wasonground;
 
 	I_Assert(mo != NULL);
 	I_Assert(!P_MobjWasRemoved(mo));
@@ -2704,6 +2710,8 @@ void P_PlayerZMovement(mobj_t *mo)
 	if (!mo->player)
 		return;
 
+	wasonground = P_IsObjectOnGround(mo);
+
 	// Intercept the stupid 'fall through 3dfloors' bug
 	if (mo->subsector->sector->ffloors)
 		P_AdjustMobjFloorZ_FFloors(mo, mo->subsector->sector, 0);
@@ -2834,6 +2842,8 @@ void P_PlayerZMovement(mobj_t *mo)
 			P_CheckGravity(mo, true);
 		}
 	}
+
+	P_CheckSectorTransitionalEffects(mo, mo->subsector->sector, wasonground);
 }
 
 boolean P_SceneryZMovement(mobj_t *mo)
@@ -10216,7 +10226,7 @@ void P_MobjThinker(mobj_t *mobj)
 	if (udmf)
 	{
 		// Check for continuous sector special actions
-		P_CheckMobjTouchingSectorActions(mobj, true);
+		P_CheckMobjTouchingSectorActions(mobj, true, true);
 	}
 	else
 	{
diff --git a/src/p_spec.c b/src/p_spec.c
index 6063a5969..1f73a6f74 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -5763,7 +5763,7 @@ static boolean P_AllowSpecialCeiling(sector_t *sec, mobj_t *thing)
 	return false;
 }
 
-static void P_CheckMobj3DFloorAction(mobj_t *mo, sector_t *sec, boolean continuous)
+static void P_CheckMobj3DFloorAction(mobj_t *mo, sector_t *sec, boolean continuous, boolean sectorchanged)
 {
 	sector_t *originalsector = mo->subsector->sector;
 	ffloor_t *rover;
@@ -5822,6 +5822,10 @@ static void P_CheckMobj3DFloorAction(mobj_t *mo, sector_t *sec, boolean continuo
 				continue;
 			}
 		}
+		else if (sectorchanged == false)
+		{
+			continue;
+		}
 
 		activator = Z_Calloc(sizeof(activator_t), PU_LEVEL, NULL);
 		I_Assert(activator != NULL);
@@ -5841,7 +5845,7 @@ static void P_CheckMobj3DFloorAction(mobj_t *mo, sector_t *sec, boolean continuo
 	}
 }
 
-static void P_CheckMobjPolyobjAction(mobj_t *mo, boolean continuous)
+static void P_CheckMobjPolyobjAction(mobj_t *mo, boolean continuous, boolean sectorchanged)
 {
 	sector_t *originalsector = mo->subsector->sector;
 	polyobj_t *po;
@@ -5896,6 +5900,10 @@ static void P_CheckMobjPolyobjAction(mobj_t *mo, boolean continuous)
 				continue;
 			}
 		}
+		else if (sectorchanged == false)
+		{
+			continue;
+		}
 
 		activator = Z_Calloc(sizeof(activator_t), PU_LEVEL, NULL);
 		I_Assert(activator != NULL);
@@ -5915,7 +5923,7 @@ static void P_CheckMobjPolyobjAction(mobj_t *mo, boolean continuous)
 	}
 }
 
-static void P_CheckMobjSectorAction(mobj_t *mo, sector_t *sec, boolean continuous)
+static void P_CheckMobjSectorAction(mobj_t *mo, sector_t *sec, boolean continuous, boolean sectorchanged)
 {
 	activator_t *activator = NULL;
 	boolean result = false;
@@ -5952,6 +5960,10 @@ static void P_CheckMobjSectorAction(mobj_t *mo, sector_t *sec, boolean continuou
 			return;
 		}
 	}
+	else if (sectorchanged == false)
+	{
+		return;
+	}
 
 	activator = Z_Calloc(sizeof(activator_t), PU_LEVEL, NULL);
 	I_Assert(activator != NULL);
@@ -5968,7 +5980,7 @@ static void P_CheckMobjSectorAction(mobj_t *mo, sector_t *sec, boolean continuou
 	}
 }
 
-void P_CheckMobjTouchingSectorActions(mobj_t *mobj, boolean continuous)
+void P_CheckMobjTouchingSectorActions(mobj_t *mobj, boolean continuous, boolean sectorchanged)
 {
 	sector_t *originalsector;
 
@@ -5994,13 +6006,13 @@ void P_CheckMobjTouchingSectorActions(mobj_t *mobj, boolean continuous)
 		}
 	}
 
-	P_CheckMobj3DFloorAction(mobj, originalsector, continuous);
+	P_CheckMobj3DFloorAction(mobj, originalsector, continuous, sectorchanged);
 	if TELEPORTED(mobj)	return;
 
-	P_CheckMobjPolyobjAction(mobj, continuous);
+	P_CheckMobjPolyobjAction(mobj, continuous, sectorchanged);
 	if TELEPORTED(mobj)	return;
 
-	P_CheckMobjSectorAction(mobj, originalsector, continuous);
+	P_CheckMobjSectorAction(mobj, originalsector, continuous, sectorchanged);
 }
 
 #undef TELEPORTED
@@ -9493,3 +9505,21 @@ void P_StartQuake(fixed_t intensity, tic_t time)
 	quake.intensity = FixedMul(intensity, mapobjectscale);
 	quake.time = time;
 }
+
+void P_CheckSectorTransitionalEffects(mobj_t *thing, sector_t *prevsec, boolean wasgrounded)
+{
+	if (!udmf)
+	{
+		return;
+	}
+
+	boolean sectorchanged = (prevsec != thing->subsector->sector);
+
+	if (!sectorchanged && wasgrounded == P_IsObjectOnGround(thing))
+	{
+		return;
+	}
+
+	// Check for each time / once sector special actions
+	P_CheckMobjTouchingSectorActions(thing, false, sectorchanged);
+}
diff --git a/src/p_spec.h b/src/p_spec.h
index 9983829f6..a4ed56192 100644
--- a/src/p_spec.h
+++ b/src/p_spec.h
@@ -543,12 +543,13 @@ sector_t *P_PlayerTouchingSectorSpecial(player_t *player, INT32 section, INT32 n
 sector_t *P_PlayerTouchingSectorSpecialFlag(player_t *player, sectorspecialflags_t flag);
 void P_PlayerInSpecialSector(player_t *player);
 void P_CheckMobjTrigger(mobj_t *mobj, boolean pushable);
-void P_CheckMobjTouchingSectorActions(mobj_t *mobj, boolean continuous);
+void P_CheckMobjTouchingSectorActions(mobj_t *mobj, boolean continuous, boolean sectorchanged);
 sector_t *P_FindPlayerTrigger(player_t *player, line_t *sourceline);
 boolean P_IsPlayerValid(size_t playernum);
 boolean P_CanPlayerTrigger(size_t playernum);
 void P_ProcessSpecialSector(player_t *player, sector_t *sector, sector_t *roversector);
 sector_t *P_ThingOnSpecial3DFloor(mobj_t *mo);
+void P_CheckSectorTransitionalEffects(mobj_t *thing, sector_t *prevsec, boolean wasgrounded);
 
 fixed_t P_FindLowestFloorSurrounding(sector_t *sec);
 fixed_t P_FindHighestFloorSurrounding(sector_t *sec);