diff --git a/src/gamedata/p_terrain.cpp b/src/gamedata/p_terrain.cpp
index 6371502c5..3391e5513 100644
--- a/src/gamedata/p_terrain.cpp
+++ b/src/gamedata/p_terrain.cpp
@@ -645,11 +645,15 @@ static void ParseFloor (FScanner &sc)
 		return;
 	}
 	sc.MustGetString ();
+	if (sc.Compare("Null") || sc.Compare("None"))
+	{
+		TerrainTypes.Set(picnum.GetIndex(), 0xffff);
+		return;
+	}
 	terrain = P_FindTerrain (sc.String);
 	if (terrain == -1)
 	{
 		Printf ("Unknown terrain %s\n", sc.String);
-		terrain = 0;
 	}
 	TerrainTypes.Set(picnum.GetIndex(), terrain);
 }
@@ -704,7 +708,7 @@ int P_FindTerrain (FName name)
 {
 	unsigned int i;
 
-	if (name == NAME_Null) return -1;
+	if (name == NAME_Null || name == NAME_None) return -1;
 	for (i = 0; i < Terrains.Size (); i++)
 	{
 		if (Terrains[i].Name == name)