diff --git a/src/thingdef/thingdef_codeptr.cpp b/src/thingdef/thingdef_codeptr.cpp
index 7ba70c2ea..ae9223319 100644
--- a/src/thingdef/thingdef_codeptr.cpp
+++ b/src/thingdef/thingdef_codeptr.cpp
@@ -663,15 +663,17 @@ void DoJumpIfCloser(AActor *target, DECLARE_PARAMINFO)
 	ACTION_PARAM_START(2);
 	ACTION_PARAM_FIXED(dist, 0);
 	ACTION_PARAM_STATE(jump, 1);
+	ACTION_PARAM_BOOL(noz, 2);
 
 	ACTION_SET_RESULT(false);	// Jumps should never set the result for inventory state chains!
 
 	// No target - no jump
-	if (target != NULL && P_AproxDistance(self->x-target->x, self->y-target->y) < dist &&
-		( (self->z > target->z && self->z - (target->z + target->height) < dist) || 
-		  (self->z <=target->z && target->z - (self->z + self->height) < dist) 
-		)
-	   )
+	if (!target)
+		return;
+	if (P_AproxDistance(self->x-target->x, self->y-target->y) < dist &&
+		(noz || 
+		((self->z > target->z && self->z - (target->z + target->height) < dist) ||
+		(self->z <= target->z && target->z - (self->z + self->height) < dist))))
 	{
 		ACTION_JUMP(jump);
 	}
diff --git a/wadsrc/static/actors/actor.txt b/wadsrc/static/actors/actor.txt
index 8969486be..18911be33 100644
--- a/wadsrc/static/actors/actor.txt
+++ b/wadsrc/static/actors/actor.txt
@@ -212,9 +212,9 @@ ACTOR Actor native //: Thinker
 	action native A_CustomBulletAttack(float spread_xy, float spread_z, int	numbullets, int damageperbullet, class<Actor> pufftype = "BulletPuff", float range = 0, int flags = 0, int ptr = AAPTR_TARGET);
 	action native A_CustomRailgun(int damage, int spawnofs_xy = 0, color color1 = "", color color2 = "", int flags = 0, bool aim = false, float maxdiff = 0, class<Actor> pufftype = "BulletPuff", float spread_xy = 0, float spread_z = 0, float range = 0, int duration = 0, float sparsity = 1.0, float driftspeed = 1.0, class<Actor> spawnclass = "none", float spawnofs_z = 0, int spiraloffset = 270);
 	action native A_JumpIfHealthLower(int health, state label, int ptr_selector = AAPTR_DEFAULT);
-	action native A_JumpIfCloser(float distance, state label);
-	action native A_JumpIfTracerCloser(float distance, state label);
-	action native A_JumpIfMasterCloser(float distance, state label);
+	action native A_JumpIfCloser(float distance, state label, bool noz = false);
+	action native A_JumpIfTracerCloser(float distance, state label, bool noz = false);
+	action native A_JumpIfMasterCloser(float distance, state label, bool noz = false);
 	action native A_JumpIfTargetOutsideMeleeRange(state label);
 	action native A_JumpIfTargetInsideMeleeRange(state label);
 	action native A_JumpIfInventory(class<Inventory> itemtype, int itemamount, state label, int owner = AAPTR_DEFAULT);