diff --git a/src/main/kotlin/one/oktw/galaxy/proxy/extension/Player.kt b/src/main/kotlin/one/oktw/galaxy/proxy/extension/Player.kt
index 4d4c964..e3408a3 100644
--- a/src/main/kotlin/one/oktw/galaxy/proxy/extension/Player.kt
+++ b/src/main/kotlin/one/oktw/galaxy/proxy/extension/Player.kt
@@ -1,6 +1,13 @@
 package one.oktw.galaxy.proxy.extension
 
 import com.velocitypowered.api.proxy.Player
-import com.velocitypowered.api.proxy.server.ServerPing
+import one.oktw.galaxy.proxy.Main.Companion.main
 
-fun Player.toSamplePlayer() = ServerPing.SamplePlayer(username, uniqueId)
+fun Player.sendPacket(o: Any) {
+    try {
+        val connection = this.javaClass.getMethod("getConnection").invoke(this)
+        connection.javaClass.getMethod("write").invoke(connection, o)
+    } catch (e: Exception) {
+        main.logger.error("Call velocity method error.", e)
+    }
+}
diff --git a/src/main/kotlin/one/oktw/galaxy/proxy/resourcepack/ResourcePackHelper.kt b/src/main/kotlin/one/oktw/galaxy/proxy/resourcepack/ResourcePackHelper.kt
index f46037d..333a1e5 100644
--- a/src/main/kotlin/one/oktw/galaxy/proxy/resourcepack/ResourcePackHelper.kt
+++ b/src/main/kotlin/one/oktw/galaxy/proxy/resourcepack/ResourcePackHelper.kt
@@ -2,11 +2,20 @@ package one.oktw.galaxy.proxy.resourcepack
 
 import com.velocitypowered.api.proxy.Player
 import one.oktw.galaxy.proxy.Main.Companion.main
+import one.oktw.galaxy.proxy.extension.sendPacket
 
 class ResourcePackHelper {
     companion object{
         fun trySendResourcePack(player: Player, galaxy: String){
             val resourcePack = main.config.galaxiesResourcePack[galaxy] ?: return
+            // workaround Minecraft 1.20.3 not auto unload old resource pack
+            try {
+                val packet = Class.forName("com.velocitypowered.proxy.protocol.packet.RemoveResourcePack").getConstructor().newInstance()
+                player.sendPacket(packet)
+            } catch (e: Exception) {
+                main.logger.error("Send remove resource pack packet error.", e)
+            }
+
             player.sendResourcePackOffer(
                 main.proxy.createResourcePackBuilder(resourcePack.uri.toString())
                     .setHash(resourcePack.hash)