diff --git a/src/p_acs.cpp b/src/p_acs.cpp
index f39a62ab98..a5cb221620 100644
--- a/src/p_acs.cpp
+++ b/src/p_acs.cpp
@@ -4184,12 +4184,12 @@ bool DLevelScript::DoCheckActorTexture(int tid, AActor *activator, int string, b
 
 	if (floor)
 	{
-		actor->Sector->NextLowestFloorAt(actor, actor->Z(), 0, &resultsec, &resffloor);
+		actor->Sector->NextLowestFloorAt(actor->X(), actor->Y(), actor->Z(), 0, actor->MaxStepHeight, &resultsec, &resffloor);
 		secpic = resffloor ? *resffloor->top.texture : resultsec->planes[sector_t::floor].Texture;
 	}
 	else
 	{
-		actor->Sector->NextHighestCeilingAt(actor, actor->Top(), 0, &resultsec, &resffloor);
+		actor->Sector->NextHighestCeilingAt(actor->X(), actor->Y(), actor->Z(), actor->Top(), 0, &resultsec, &resffloor);
 		secpic = resffloor ? *resffloor->bottom.texture : resultsec->planes[sector_t::ceiling].Texture;
 	}
 	return tex == TexMan[secpic];
diff --git a/src/p_map.cpp b/src/p_map.cpp
index 433e9d5f3b..8c9b210555 100644
--- a/src/p_map.cpp
+++ b/src/p_map.cpp
@@ -290,7 +290,7 @@ void P_GetFloorCeilingZ(FCheckPosition &tmf, int flags)
 	sector_t *sec = (!(flags & FFCF_SAMESECTOR) || tmf.thing->Sector == NULL)? P_PointInSector(tmf.x, tmf.y) : tmf.sector;
 	F3DFloor *ffc, *fff;
 
-	tmf.ceilingz = sec->NextHighestCeilingAt(tmf.x, tmf.y, tmf.z + tmf.thing->height, flags, &tmf.ceilingsector, &ffc);
+	tmf.ceilingz = sec->NextHighestCeilingAt(tmf.x, tmf.y, tmf.z, tmf.z + tmf.thing->height, flags, &tmf.ceilingsector, &ffc);
 	tmf.floorz = tmf.dropoffz = sec->NextLowestFloorAt(tmf.x, tmf.y, tmf.z, flags, tmf.thing->MaxStepHeight, &tmf.floorsector, &fff);
 
 	if (fff)
diff --git a/src/p_sectors.cpp b/src/p_sectors.cpp
index d9cd733cb6..27c8493ea6 100644
--- a/src/p_sectors.cpp
+++ b/src/p_sectors.cpp
@@ -932,7 +932,7 @@ fixed_t sector_t::LowestFloorAt(fixed_t x, fixed_t y, sector_t **resultsec)
 }
 
 
-fixed_t sector_t::NextHighestCeilingAt(fixed_t x, fixed_t y, fixed_t z, int flags, sector_t **resultsec, F3DFloor **resultffloor)
+fixed_t sector_t::NextHighestCeilingAt(fixed_t x, fixed_t y, fixed_t bottomz, fixed_t topz, int flags, sector_t **resultsec, F3DFloor **resultffloor)
 {
 	sector_t *sec = this;
 	fixed_t planeheight = FIXED_MIN;
@@ -943,14 +943,20 @@ fixed_t sector_t::NextHighestCeilingAt(fixed_t x, fixed_t y, fixed_t z, int flag
 		fixed_t realceil = sec->ceilingplane.ZatPoint(x, y);
 		for (int i = sec->e->XFloor.ffloors.Size() - 1; i >= 0; --i)
 		{
-			F3DFloor *ff = sec->e->XFloor.ffloors[i];
+			F3DFloor *rover = sec->e->XFloor.ffloors[i];
+			if (!(rover->flags & FF_SOLID) || !(rover->flags & FF_EXISTS)) continue;
 
-			fixed_t ffz = ff->bottom.plane->ZatPoint(x, y);
-			if (ffz < realceil && ((ff->flags & (FF_EXISTS | FF_SOLID)) == (FF_EXISTS | FF_SOLID) && z <= ffz))
-			{ // This floor is above our eyes.
+			fixed_t ff_bottom = rover->bottom.plane->ZatPoint(x, y);
+			fixed_t ff_top = rover->top.plane->ZatPoint(x, y);
+
+			fixed_t delta1 = bottomz - (ff_bottom + ((ff_top - ff_bottom) / 2));
+			fixed_t delta2 = topz - (ff_bottom + ((ff_top - ff_bottom) / 2));
+
+			if (ff_bottom < realceil && abs(delta1) >= abs(delta2))
+			{ 
 				if (resultsec) *resultsec = sec;
-				if (resultffloor) *resultffloor = ff;
-				return ffz;
+				if (resultffloor) *resultffloor = rover;
+				return ff_bottom;
 			}
 		}
 		if ((flags & FFCF_NOPORTALS) || sec->PortalBlocksMovement(ceiling) || planeheight >= sec->SkyBoxes[ceiling]->threshold)
diff --git a/src/r_defs.h b/src/r_defs.h
index 3e6574e561..d04afbf880 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -820,19 +820,9 @@ struct sector_t
 		return LowestFloorAt(a->X(), a->Y(), resultsec);
 	}
 
-	fixed_t NextHighestCeilingAt(fixed_t x, fixed_t y, fixed_t z, int flags = 0, sector_t **resultsec = NULL, F3DFloor **resultffloor = NULL);
+	fixed_t NextHighestCeilingAt(fixed_t x, fixed_t y, fixed_t bottomz, fixed_t topz, int flags = 0, sector_t **resultsec = NULL, F3DFloor **resultffloor = NULL);
 	fixed_t NextLowestFloorAt(fixed_t x, fixed_t y, fixed_t z, int flags = 0, fixed_t steph = 0, sector_t **resultsec = NULL, F3DFloor **resultffloor = NULL);
 
-	fixed_t NextHighestCeilingAt(AActor *a, fixed_t z, int flags = 0, sector_t **resultsec = NULL, F3DFloor **resultffloor = NULL)
-	{
-		return NextHighestCeilingAt(a->X(), a->Y(), z, flags, resultsec, resultffloor);
-	}
-
-	fixed_t NextLowestFloorAt(AActor *a, fixed_t z, int flags, sector_t **resultsec = NULL, F3DFloor **resultffloor = NULL)
-	{
-		return NextLowestFloorAt(a->X(), a->Y(), z, flags, a->MaxStepHeight, resultsec, resultffloor);
-	}
-
 	// Member variables
 	fixed_t		CenterFloor () const { return floorplane.ZatPoint (centerspot); }
 	fixed_t		CenterCeiling () const { return ceilingplane.ZatPoint (centerspot); }