diff --git a/src/p_setup.cpp b/src/p_setup.cpp
index 54680ba603..f25a2050e8 100644
--- a/src/p_setup.cpp
+++ b/src/p_setup.cpp
@@ -1096,6 +1096,7 @@ void P_LoadSectors (MapData *map, FMissingTextureTracker &missingtex)
 		ss->nextsec = -1;	//jff 2/26/98 add fields to support locking out
 		ss->prevsec = -1;	// stair retriggering until build completes
 		memset(ss->SpecialColors, -1, sizeof(ss->SpecialColors));
+		ss->SpecialColors[sector_t::add] = 0;
 
 		ss->SetAlpha(sector_t::floor, 1.);
 		ss->SetAlpha(sector_t::ceiling, 1.);
diff --git a/src/p_udmf.cpp b/src/p_udmf.cpp
index 95d3f06b90..2c1bd13e0e 100644
--- a/src/p_udmf.cpp
+++ b/src/p_udmf.cpp
@@ -1453,6 +1453,7 @@ public:
 		sec->terrainnum[sector_t::ceiling] = sec->terrainnum[sector_t::floor] = -1;
 		sec->ibocount = -1;
 		memset(sec->SpecialColors, -1, sizeof(sec->SpecialColors));
+		sec->SpecialColors[sector_t::add] = 0;
 		if (floordrop) sec->Flags = SECF_FLOORDROP;
 		// killough 3/7/98: end changes