diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 905f68c4c..549028cdb 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -1420,7 +1420,7 @@ void P_LoadSectors (MapData * map)
 		ss->nextsec = -1;	//jff 2/26/98 add fields to support locking out
 		ss->prevsec = -1;	// stair retriggering until build completes
 
-		ss->SetAlpha(sector_t::ceiling, FRACUNIT);
+		ss->SetAlpha(sector_t::floor, FRACUNIT);
 		ss->SetAlpha(sector_t::ceiling, FRACUNIT);
 		ss->SetXScale(sector_t::floor, FRACUNIT);	// [RH] floor and ceiling scaling
 		ss->SetYScale(sector_t::floor, FRACUNIT);