diff --git a/Spigot-Server-Patches/0433-Allow-login-events-to-fire-only-after-the-server-plu.patch b/Spigot-Server-Patches/0433-Allow-login-events-to-fire-only-after-the-server-plu.patch
new file mode 100644
index 0000000000..3cc4c1f497
--- /dev/null
+++ b/Spigot-Server-Patches/0433-Allow-login-events-to-fire-only-after-the-server-plu.patch
@@ -0,0 +1,72 @@
+From c285a117f05799e780ccde777d07772c5cacbc05 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <Spottedleaf@users.noreply.github.com>
+Date: Sun, 31 Mar 2019 22:02:24 -0700
+Subject: [PATCH] Allow login events to fire only after the server plugins are
+ enabled
+
+Event threads will simply block until they're ready to accept.
+
+diff --git a/src/main/java/net/minecraft/server/LoginListener.java b/src/main/java/net/minecraft/server/LoginListener.java
+index dfe7a029f..503f66582 100644
+--- a/src/main/java/net/minecraft/server/LoginListener.java
++++ b/src/main/java/net/minecraft/server/LoginListener.java
+@@ -282,6 +282,36 @@ public class LoginListener implements PacketLoginInListener, ITickable {
+         }
+     }
+ 
++    // Paper start - Delay async prelogin until plugins are ready
++    private static volatile Object blockingLogins = new Object();
++
++    public static void checkStartupAndBlock() {
++        final Object lock = LoginListener.blockingLogins;
++        if (lock != null) {
++            synchronized (lock) {
++                for (;;) {
++                    if (LoginListener.blockingLogins == null) {
++                        return;
++                    }
++                    try {
++                        lock.wait();
++                    } catch (final InterruptedException ignore) {// handled by the if statement above
++                        Thread.currentThread().interrupt();
++                    }
++                }
++            }
++        }
++    }
++
++    public static void allowLogins() {
++        final Object lock = LoginListener.blockingLogins;
++        synchronized (lock) {
++            LoginListener.blockingLogins = null;
++            lock.notifyAll();
++        }
++    }
++    // Paper end
++
+     // Spigot start
+     public class LoginHandler {
+ 
+@@ -292,6 +322,7 @@ public class LoginListener implements PacketLoginInListener, ITickable {
+                                 return;
+                             }
+                             // Paper end
++                            LoginListener.checkStartupAndBlock(); // Paper - Delay async login events until plugins are ready
+                             String playerName = i.getName();
+                             java.net.InetAddress address = ((java.net.InetSocketAddress) networkManager.getSocketAddress()).getAddress();
+                             java.util.UUID uniqueId = i.getId();
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index d6250c472..8db5c6a35 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -606,6 +606,7 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
+         this.x = 0;
+         // CraftBukkit Start
+         this.server.enablePlugins(org.bukkit.plugin.PluginLoadOrder.POSTWORLD);
++        LoginListener.allowLogins(); // Paper - Allow logins once postworld
+         this.server.getPluginManager().callEvent(new ServerLoadEvent(ServerLoadEvent.LoadType.STARTUP));
+         // CraftBukkit end
+     }
+-- 
+2.21.0
+