diff --git a/changelog.md b/changelog.md
index 11b8002..8378dea 100644
--- a/changelog.md
+++ b/changelog.md
@@ -12,6 +12,7 @@ These changes will (most likely) be included in the next version.
 
 ## [Unreleased]
 - It is no longer necessary to have recurrent waves for an arena to work. MobArena automatically creates a "catch all" recurrent wave in case the arena session reaches a wave number that isn't covered by any other wave definitions.
+- Entities outside of the arena can no longer target players, pets, or monsters inside of the arena.
 
 ## [0.104] - 2019-08-08
 - Extended and upgraded potions are now supported in the item syntax by prepending `long_` or `strong_` to the data portion of a potion item (e.g. `potion:strong_instant_heal:1` will yield a Potion of Healing II). Check the wiki for details.
diff --git a/src/main/java/com/garbagemule/MobArena/ArenaListener.java b/src/main/java/com/garbagemule/MobArena/ArenaListener.java
index 1cd7f4f..31a7a9a 100644
--- a/src/main/java/com/garbagemule/MobArena/ArenaListener.java
+++ b/src/main/java/com/garbagemule/MobArena/ArenaListener.java
@@ -828,35 +828,73 @@ public class ArenaListener
         Entity entity = event.getEntity();
         Entity target = event.getTarget();
 
-        if (arena.hasPet(entity)) {
-            // Pets should never attack players
-            if (target instanceof Player) {
-                event.setCancelled(true);
-            }
+        if (isArenaPet(entity)) {
+            onPetTarget(event, target);
+        } else if (isArenaMonster(entity)) {
+            onMonsterTarget(event, entity, target);
+        } else {
+            onForeignTarget(event, target);
+        }
+    }
+
+    private void onPetTarget(EntityTargetEvent event, Entity target) {
+        // If the target is null, do nothing
+        if (target == null) {
+            return;
         }
 
-        else if (monsters.getMonsters().contains(entity)) {
-            // If the target is null, we probably forgot or the target died
-            if (target == null) {
-                event.setTarget(MAUtils.getClosestPlayer(plugin, entity, arena));
-            }
-
-            // Pets are untargetable
-            else if (arena.hasPet(target)) {
-                event.setCancelled(true);
-            }
-
-            // So are non-arena players
-            else if (target instanceof Player && !arena.inArena((Player) target)) {
-                event.setCancelled(true);
-            }
-
-            // And other mobs unless infighting is enabled
-            else if (monsters.getMonsters().contains(target) && !monsterInfight) {
-                event.setCancelled(true);
-            }
+        // Pets should only attack monsters in the arena, nothing else
+        if (!isArenaMonster(target)) {
+            event.setCancelled(true);
         }
     }
+
+    private void onMonsterTarget(EntityTargetEvent event, Entity monster, Entity target) {
+        // Null means we lost our target or the target died, so find a new one
+        if (target == null) {
+            event.setTarget(MAUtils.getClosestPlayer(plugin, monster, arena));
+            return;
+        }
+
+        // If monster infighting is on and target is monster, let it happen
+        if (monsterInfight && isArenaMonster(target)) {
+            return;
+        }
+
+        // At this point, if the target is _not_ an arena player, we can just
+        // cancel, because this check also covers the target being a pet, an
+        // arena monster when infighting is off (due to the check above), or
+        // any foreign entity.
+        if (!isArenaPlayer(target)) {
+            event.setCancelled(true);
+        }
+    }
+
+    private void onForeignTarget(EntityTargetEvent event, Entity target) {
+        // If null, just bail
+        if (target == null) {
+            return;
+        }
+
+        // Foreign entities can't target arena pets, -players, or -monsters.
+        if (isArenaPet(target) || isArenaPlayer(target) || isArenaMonster(target)) {
+            event.setCancelled(true);
+        }
+    }
+
+    @SuppressWarnings("SuspiciousMethodCalls")
+    private boolean isArenaPlayer(Entity entity) {
+        return arena.getPlayersInArena().contains(entity);
+    }
+
+    @SuppressWarnings("SuspiciousMethodCalls")
+    private boolean isArenaMonster(Entity entity) {
+        return monsters.getMonsters().contains(entity);
+    }
+
+    private boolean isArenaPet(Entity entity) {
+        return arena.hasPet(entity);
+    }
     
     public void onEntityTeleport(EntityTeleportEvent event) {
         if (monsters.hasPet(event.getEntity()) && region.contains(event.getTo())) {