diff --git a/SpigotCore_15/src/de/steamwar/authlib/AuthlibInjector_15.java b/SpigotCore_15/src/de/steamwar/authlib/AuthlibInjector_15.java
new file mode 100644
index 0000000..9864a31
--- /dev/null
+++ b/SpigotCore_15/src/de/steamwar/authlib/AuthlibInjector_15.java
@@ -0,0 +1,33 @@
+/*
+ *    This file is a part of the SteamWar software.
+ *
+ *    Copyright (C) 2020  SteamWar.de-Serverteam
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Affero General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.authlib;
+
+import net.minecraft.server.v1_15_R1.MinecraftServer;
+
+public class AuthlibInjector_15 {
+
+    static Class getMinecraftClass() {
+        return MinecraftServer.class;
+    }
+
+    static Object getMinecraftServerInstance() {
+        return MinecraftServer.getServer();
+    }
+}
diff --git a/SpigotCore_Main/src/de/steamwar/authlib/AuthlibInjector.java b/SpigotCore_Main/src/de/steamwar/authlib/AuthlibInjector.java
new file mode 100644
index 0000000..b96f71c
--- /dev/null
+++ b/SpigotCore_Main/src/de/steamwar/authlib/AuthlibInjector.java
@@ -0,0 +1,46 @@
+/*
+ *    This file is a part of the SteamWar software.
+ *
+ *    Copyright (C) 2020  SteamWar.de-Serverteam
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Affero General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.authlib;
+
+import com.mojang.authlib.yggdrasil.YggdrasilGameProfileRepository;
+import de.steamwar.core.Core;
+import de.steamwar.core.VersionedCallable;
+
+import java.lang.reflect.Field;
+
+public class AuthlibInjector {
+
+    public static void inject() {
+        if(Core.getVersion() < 15) {
+            return;
+        }
+        try {
+            Class<?> minecraftServerClass = VersionedCallable.call(new VersionedCallable<>(() -> AuthlibInjector_15.getMinecraftClass(), 15));
+            Field repo = minecraftServerClass.getDeclaredField("gameProfileRepository");
+            repo.setAccessible(true);
+            Object instance = VersionedCallable.call(new VersionedCallable<>(() -> AuthlibInjector_15.getMinecraftServerInstance(), 15));
+            repo.set(instance, new SteamwarGameProfileRepository((YggdrasilGameProfileRepository) repo.get(instance)));
+        } catch (NoSuchFieldException e) {
+            e.printStackTrace();
+        } catch (IllegalAccessException e) {
+            e.printStackTrace();
+        }
+    }
+}
diff --git a/SpigotCore_Main/src/de/steamwar/authlib/SteamwarGameProfileRepository.java b/SpigotCore_Main/src/de/steamwar/authlib/SteamwarGameProfileRepository.java
new file mode 100644
index 0000000..20bcc9c
--- /dev/null
+++ b/SpigotCore_Main/src/de/steamwar/authlib/SteamwarGameProfileRepository.java
@@ -0,0 +1,61 @@
+/*
+ *    This file is a part of the SteamWar software.
+ *
+ *    Copyright (C) 2020  SteamWar.de-Serverteam
+ *
+ *    This program is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Affero General Public License as published by
+ *    the Free Software Foundation, either version 3 of the License, or
+ *    (at your option) any later version.
+ *
+ *    This program is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ *    GNU Affero General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Affero General Public License
+ *    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.authlib;
+
+import com.mojang.authlib.Agent;
+import com.mojang.authlib.GameProfile;
+import com.mojang.authlib.GameProfileRepository;
+import com.mojang.authlib.ProfileLookupCallback;
+import com.mojang.authlib.yggdrasil.YggdrasilGameProfileRepository;
+import de.steamwar.sql.SteamwarUser;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class SteamwarGameProfileRepository implements GameProfileRepository {
+
+    private final YggdrasilGameProfileRepository fallback;
+
+    public SteamwarGameProfileRepository(YggdrasilGameProfileRepository repository) {
+        fallback = repository;
+    }
+
+    @Override
+    public void findProfilesByNames(String[] strings, Agent agent, ProfileLookupCallback profileLookupCallback) {
+        System.out.println("Call!!");
+        if(agent == Agent.SCROLLS) {
+            fallback.findProfilesByNames(strings, agent, profileLookupCallback);
+        } else {
+            List<String> unknownNames = new ArrayList<>();
+            for (String name:strings) {
+                SteamwarUser user = SteamwarUser.get(name);
+                if(user == null) {
+                    unknownNames.add(name);
+                    continue;
+                }
+
+                profileLookupCallback.onProfileLookupSucceeded(new GameProfile(user.getUUID(), user.getUserName()));
+            }
+            if(!unknownNames.isEmpty()) {
+                fallback.findProfilesByNames(unknownNames.toArray(new String[0]), agent, profileLookupCallback);
+            }
+        }
+    }
+}
diff --git a/SpigotCore_Main/src/de/steamwar/core/Core.java b/SpigotCore_Main/src/de/steamwar/core/Core.java
index d9c59df..62f8849 100644
--- a/SpigotCore_Main/src/de/steamwar/core/Core.java
+++ b/SpigotCore_Main/src/de/steamwar/core/Core.java
@@ -19,6 +19,7 @@
 
 package de.steamwar.core;
 
+import de.steamwar.authlib.AuthlibInjector;
 import de.steamwar.comms.BungeeReceiver;
 import de.steamwar.core.events.ChattingEvent;
 import de.steamwar.core.events.ChunkListener;
@@ -64,6 +65,7 @@ public class Core extends JavaPlugin{
 			ErrorLogger.init();
 		getServer().getMessenger().registerIncomingPluginChannel(this, "sw:bridge", new BungeeReceiver());
 		getServer().getMessenger().registerOutgoingPluginChannel(this, "sw:bridge");
+		AuthlibInjector.inject();
 	}
 
 	@Override