diff --git a/wadsrc/static/zscript/constants.zs b/wadsrc/static/zscript/constants.zs
index 8e31a68ea..fe44f2c3d 100644
--- a/wadsrc/static/zscript/constants.zs
+++ b/wadsrc/static/zscript/constants.zs
@@ -1429,6 +1429,10 @@ enum ECompatFlags
 	COMPATF2_EXPLODE1		= 1 << 8,	// No vertical explosion thrust
 	COMPATF2_EXPLODE2		= 1 << 9,	// Use original explosion code throughout.
 	COMPATF2_RAILING		= 1 << 10,	// Bugged Strife railings.
+	COMPATF2_SCRIPTWAIT		= 1 << 11,	// Use old scriptwait implementation where it doesn't wait on a non-running script.
+	COMPATF2_AVOID_HAZARDS	= 1 << 12,	// another MBF thing.
+	COMPATF2_STAYONLIFT		= 1 << 13,	// yet another MBF thing.
+	COMPATF2_NOMBF21		= 1 << 14,	// disable MBF21 features that may clash with certain maps
 	COMPATF2_VOODOO_ZOMBIES = 1 << 15,  // allow playerinfo, playerpawn, and voodoo health to all be different, and allow monster targetting of 'dead' players that have positive health
 };