--- a/net/minecraft/server/CustomFunctionData.java
+++ b/net/minecraft/server/CustomFunctionData.java
@@ -33,7 +33,7 @@
         }
 
         public World getWorld() {
-            return CustomFunctionData.this.c.worldServer[0];
+            return CustomFunctionData.this.c.worlds.get(0); // CraftBukkit
         }
 
         public MinecraftServer C_() {
@@ -57,7 +57,7 @@
     }
 
     public int c() {
-        return this.c.worldServer[0].getGameRules().c("maxCommandChainLength");
+        return this.c.worlds.get(0).getGameRules().c("maxCommandChainLength"); // CraftBukkit
     }
 
     public Map<MinecraftKey, CustomFunction> d() {
@@ -65,7 +65,7 @@
     }
 
     public void e() {
-        String s = this.c.worldServer[0].getGameRules().get("gameLoopFunction");
+        String s = this.c.worlds.get(0).getGameRules().get("gameLoopFunction"); // CraftBukkit
 
         if (!s.equals(this.e)) {
             this.e = s;