diff --git a/src/g_heretic/a_hereticartifacts.cpp b/src/g_heretic/a_hereticartifacts.cpp
index 169d0e771..f2ad18b2f 100644
--- a/src/g_heretic/a_hereticartifacts.cpp
+++ b/src/g_heretic/a_hereticartifacts.cpp
@@ -44,18 +44,6 @@ bool AArtiTomeOfPower::Use (bool pickup)
 
 // Time bomb ----------------------------------------------------------------
 
-DEFINE_ACTION_FUNCTION(AActor, A_TimeBomb)
-{
-	PARAM_SELF_PROLOGUE(AActor);
-
-	self->AddZ(32, false);
-	self->RenderStyle = STYLE_Add;
-	self->Alpha = 1.;
-	P_RadiusAttack (self, self->target, 128, 128, self->DamageType, RADF_HURTSOURCE);
-	P_CheckSplash(self, 128);
-	return 0;
-}
-
 class AArtiTimeBomb : public AInventory
 {
 	DECLARE_CLASS (AArtiTimeBomb, AInventory)
diff --git a/src/p_mobj.cpp b/src/p_mobj.cpp
index 52541a669..abbd057d7 100644
--- a/src/p_mobj.cpp
+++ b/src/p_mobj.cpp
@@ -6956,7 +6956,8 @@ DEFINE_ACTION_FUNCTION(AActor, AddZ)
 {
 	PARAM_SELF_PROLOGUE(AActor);
 	PARAM_FLOAT(addz);
-	self->AddZ(addz);
+	PARAM_BOOL_DEF(moving);
+	self->AddZ(addz, moving);
 	return 0;
 }
 
diff --git a/wadsrc/static/zscript/actor.txt b/wadsrc/static/zscript/actor.txt
index 9980d28f5..7b6b63672 100644
--- a/wadsrc/static/zscript/actor.txt
+++ b/wadsrc/static/zscript/actor.txt
@@ -108,7 +108,7 @@ class Actor : Thinker native
 	native void UnlinkFromWorld();
 	native bool CanSeek(Actor target);
 	native double AngleTo(Actor target, bool absolute = false);
-	native void AddZ(float zadd);
+	native void AddZ(float zadd, bool moving = true);
 	native void SetZ(float z);
 	native vector3 Vec3Offset(float x, float y, float z, bool absolute = false);
 	native vector3 Vec3Angle(float length, float angle, float z = 0, bool absolute = false);
diff --git a/wadsrc/static/zscript/heretic/hereticartifacts.txt b/wadsrc/static/zscript/heretic/hereticartifacts.txt
index e239748ff..50a25008a 100644
--- a/wadsrc/static/zscript/heretic/hereticartifacts.txt
+++ b/wadsrc/static/zscript/heretic/hereticartifacts.txt
@@ -80,8 +80,6 @@ Class ActivatedTimeBomb : Actor
 		DeathSound "misc/timebomb";
 	}
 		
-	native void A_Timebomb();
-	
 	States
 	{
 	Spawn:
@@ -91,6 +89,13 @@ Class ActivatedTimeBomb : Actor
 		XPL1 BCDEF 4 BRIGHT;
 		Stop;
 	}
+
+	void A_TimeBomb()
+	{
+		AddZ(32, false);
+		A_SetRenderStyle(1., STYLE_Add);
+		A_Explode();
+	}
 }
 
 
diff --git a/wadsrc/static/zscript/hexen/dragon.txt b/wadsrc/static/zscript/hexen/dragon.txt
index ed6e86d4a..6082d1c61 100644
--- a/wadsrc/static/zscript/hexen/dragon.txt
+++ b/wadsrc/static/zscript/hexen/dragon.txt
@@ -291,7 +291,7 @@ class Dragon : Actor
 
 	void A_DragonCheckCrash()
 	{
-		if (pos.z < floorz)
+		if (pos.z <= floorz)
 		{
 			SetStateLabel ("Crash");
 		}
diff --git a/wadsrc/static/zscript/hexen/flechette.txt b/wadsrc/static/zscript/hexen/flechette.txt
index 6f7b3a818..c02477064 100644
--- a/wadsrc/static/zscript/hexen/flechette.txt
+++ b/wadsrc/static/zscript/hexen/flechette.txt
@@ -37,8 +37,6 @@ class FireBomb : Actor
 		DeathSound "FlechetteExplode";
 	}
 
-	native void A_TimeBomb();
-
 	States
 	{
 	Spawn:
@@ -50,6 +48,13 @@ class FireBomb : Actor
 		XPL1 BCDEF 4 Bright;
 		Stop;
 	}
+
+	void A_TimeBomb()
+	{
+		AddZ(32, false);
+		A_SetRenderStyle(1., STYLE_Add);
+		A_Explode();
+	}
 }
 
 // Throwing Bomb (Flechette used by Fighter) --------------------------------