--- a/net/minecraft/server/bossevents/BossBattleCustom.java
+++ b/net/minecraft/server/bossevents/BossBattleCustom.java
@@ -18,6 +18,11 @@
 import net.minecraft.util.MathHelper;
 import net.minecraft.world.BossBattle;
 
+// CraftBukkit start
+import org.bukkit.boss.KeyedBossBar;
+import org.bukkit.craftbukkit.boss.CraftKeyedBossbar;
+// CraftBukkit end
+
 public class BossBattleCustom extends BossBattleServer {
 
     private static final int DEFAULT_MAX = 100;
@@ -25,6 +30,16 @@
     private final Set<UUID> players = Sets.newHashSet();
     private int value;
     private int max = 100;
+    // CraftBukkit start
+    private KeyedBossBar bossBar;
+
+    public KeyedBossBar getBukkitEntity() {
+        if (bossBar == null) {
+            bossBar = new CraftKeyedBossbar(this);
+        }
+        return bossBar;
+    }
+    // CraftBukkit end
 
     public BossBattleCustom(MinecraftKey minecraftkey, IChatBaseComponent ichatbasecomponent) {
         super(ichatbasecomponent, BossBattle.BarColor.WHITE, BossBattle.BarStyle.PROGRESS);
@@ -145,7 +160,7 @@
         bossbattlecustom.setDarkenScreen(bossbattlecustom_a.darkenScreen);
         bossbattlecustom.setPlayBossMusic(bossbattlecustom_a.playBossMusic);
         bossbattlecustom.setCreateWorldFog(bossbattlecustom_a.createWorldFog);
-        Set set = bossbattlecustom_a.players;
+        Set<UUID> set = bossbattlecustom_a.players; // CraftBukkit - decompile error
 
         Objects.requireNonNull(bossbattlecustom);
         set.forEach(bossbattlecustom::addOfflinePlayer);