diff --git a/src/main/java/net/minecraft/server/Entity.java b/src/main/java/net/minecraft/server/Entity.java
index e1d611ed38..dffa97fbe7 100644
--- a/src/main/java/net/minecraft/server/Entity.java
+++ b/src/main/java/net/minecraft/server/Entity.java
@@ -1750,10 +1750,20 @@ public abstract class Entity {
             MinecraftServer minecraftserver = MinecraftServer.getServer();
             // CraftBukkit start - move logic into new function "teleportToLocation"
             // int j = this.dimension;
-            Location enter = this.getBukkitEntity().getLocation();
-            Location exit = minecraftserver.getPlayerList().calculateTarget(enter, minecraftserver.getWorldServer(i));
+            WorldServer exitWorld = null;
+            if (this.dimension < CraftWorld.CUSTOM_DIMENSION_OFFSET) { // plugins must specify exit from custom Bukkit worlds
+                // only target existing worlds (compensate for allow-nether/allow-end as false)
+                for (WorldServer world : minecraftserver.worlds) {
+                    if (world.dimension == i) {
+                        exitWorld = world;
+                    }
+                }
+            }
 
-            TravelAgent agent = (TravelAgent) ((CraftWorld) exit.getWorld()).getHandle().s();
+            Location enter = this.getBukkitEntity().getLocation();
+            Location exit = exitWorld != null ? minecraftserver.getPlayerList().calculateTarget(enter, minecraftserver.getWorldServer(i)) : null;
+
+            TravelAgent agent = exit != null ? (TravelAgent) ((CraftWorld) exit.getWorld()).getHandle().s() : null;
             EntityPortalEvent event = new EntityPortalEvent(this.getBukkitEntity(), enter, exit, agent);
             event.getEntity().getServer().getPluginManager().callEvent(event);
             if (event.isCancelled() || event.getTo() == null || !this.isAlive()) {
diff --git a/src/main/java/net/minecraft/server/PlayerList.java b/src/main/java/net/minecraft/server/PlayerList.java
index 2fb83cf6cc..f669a00b05 100644
--- a/src/main/java/net/minecraft/server/PlayerList.java
+++ b/src/main/java/net/minecraft/server/PlayerList.java
@@ -424,23 +424,35 @@ public abstract class PlayerList {
 
     // CraftBukkit start - Replaced the standard handling of portals with a more customised method.
     public void changeDimension(EntityPlayer entityplayer, int i, TeleportCause cause) {
-        WorldServer exitWorld = this.server.getWorldServer(i);
-        Location enter = entityplayer.getBukkitEntity().getLocation();
-        Location exit = null;
-        if ((cause == TeleportCause.END_PORTAL) && (i == 0)) {
-            // THE_END -> NORMAL; use bed if available
-            exit = ((CraftPlayer) entityplayer.getBukkitEntity()).getBedSpawnLocation();
-        }
-        if (exit == null) {
-            exit = this.calculateTarget(enter, exitWorld);
+        WorldServer exitWorld = null;
+        if (entityplayer.dimension < CraftWorld.CUSTOM_DIMENSION_OFFSET) { // plugins must specify exit from custom Bukkit worlds
+            // only target existing worlds (compensate for allow-nether/allow-end as false)
+            for (WorldServer world : this.server.worlds) {
+                if (world.dimension == i) {
+                    exitWorld = world;
+                }
+            }
         }
 
-        TravelAgent agent = (TravelAgent) ((CraftWorld) exit.getWorld()).getHandle().s();
+        Location enter = entityplayer.getBukkitEntity().getLocation();
+        Location exit = null;
+        if (exitWorld != null) {
+            if ((cause == TeleportCause.END_PORTAL) && (i == 0)) {
+                // THE_END -> NORMAL; use bed if available
+                exit = ((CraftPlayer) entityplayer.getBukkitEntity()).getBedSpawnLocation();
+            }
+            if (exit == null) {
+                exit = this.calculateTarget(enter, exitWorld);
+            }
+        }
+
+        TravelAgent agent = exit != null ? (TravelAgent) ((CraftWorld) exit.getWorld()).getHandle().s() : null;
         PlayerPortalEvent event = new PlayerPortalEvent(entityplayer.getBukkitEntity(), enter, exit, agent, cause);
         Bukkit.getServer().getPluginManager().callEvent(event);
         if (event.isCancelled() || event.getTo() == null) {
             return;
         }
+
         exit = event.useTravelAgent() ? event.getPortalTravelAgent().findOrCreate(exit) : event.getTo();
         exitWorld = ((CraftWorld) exit.getWorld()).getHandle();
 
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftServer.java b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
index eecededea3..e7c0760fd4 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftServer.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftServer.java
@@ -694,7 +694,7 @@ public final class CraftServer implements Server {
             converter.convert(name, new ConvertProgressUpdater(console));
         }
 
-        int dimension = 10 + console.worlds.size();
+        int dimension = CraftWorld.CUSTOM_DIMENSION_OFFSET + console.worlds.size();
         boolean used = false;
         do {
             for (WorldServer server : console.worlds) {
diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index cb200667c4..6e364b1a82 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -49,6 +49,8 @@ import org.bukkit.plugin.messaging.StandardMessenger;
 import org.bukkit.craftbukkit.util.LongHash;
 
 public class CraftWorld implements World {
+    public static final int CUSTOM_DIMENSION_OFFSET = 10;
+
     private final WorldServer world;
     private Environment environment;
     private final CraftServer server = (CraftServer) Bukkit.getServer();