diff --git a/src/lua_maplib.c b/src/lua_maplib.c
index 0051718c3..f65ea852f 100644
--- a/src/lua_maplib.c
+++ b/src/lua_maplib.c
@@ -240,6 +240,7 @@ static const char *const ffloor_opt[] = {
 	"t_slope",
 	"b_slope",
 	"sector", // secnum pushed as control sector userdata
+	"fofflags",
 	"flags",
 	"master", // control linedef
 	"target", // target sector