diff --git a/zdefs.acs b/zdefs.acs
index c4dd410..f701d51 100644
--- a/zdefs.acs
+++ b/zdefs.acs
@@ -1109,6 +1109,7 @@
 #define QF_GROUNDONLY		1 << 7
 #define QF_AFFECTACTORS 	1 << 8
 #define QF_SHAKEONLY		1 << 9
+#define QF_DAMAGEFALLOFF	1 << 10
 
 #define WARPF_ABSOLUTEOFFSET 0x1
 #define WARPF_ABSOLUTEANGLE 0x2
diff --git a/zspecial.acs b/zspecial.acs
index 33ac972..8c41d20 100644
--- a/zspecial.acs
+++ b/zspecial.acs
@@ -376,7 +376,7 @@ special
 	-88:SetActorRoll(2),
 	-89:ChangeActorRoll(2,3),
 	-90:GetActorRoll(1),
-	-91:QuakeEx(8,16),
+	-91:QuakeEx(8,19),
 	-92:Warp(6,11),
 	-93:GetMaxInventory(2),
 	-94:SetSectorDamage(2,5),