diff --git a/bridge-protocol/build.gradle b/bridge-protocol/build.gradle
index 03006c3..d5c8f11 100644
--- a/bridge-protocol/build.gradle
+++ b/bridge-protocol/build.gradle
@@ -6,7 +6,7 @@ task jar(type: Jar, overwrite: true) {
 }
 
 ext {
-    nettyVersion = '4.1.9.Final'
+    nettyVersion = '4.0.23.Final'
 }
 
 dependencies {
diff --git a/bridge-protocol/src/main/java/asys/mcsmanager/packets/codec/Params.java b/bridge-protocol/src/main/java/asys/mcsmanager/packets/codec/Params.java
index 255d55c..dc61e1b 100644
--- a/bridge-protocol/src/main/java/asys/mcsmanager/packets/codec/Params.java
+++ b/bridge-protocol/src/main/java/asys/mcsmanager/packets/codec/Params.java
@@ -12,6 +12,6 @@ import io.netty.util.AttributeKey;
 import java.util.Map;
 
 public final class Params {
-    public static final AttributeKey<BiMap<Integer, Class<? extends Packet>>> KNOWN_PACKETS = AttributeKey.newInstance("KNOWN_PACKETS");
-    public static final AttributeKey<Map<Class<? extends Packet>, IPacketHandler>> KNOWN_HANDLERS = AttributeKey.newInstance("KNOWN_HANDLERS");
+    public static final AttributeKey<BiMap<Integer, Class<? extends Packet>>> KNOWN_PACKETS = AttributeKey.valueOf("KNOWN_PACKETS");
+    public static final AttributeKey<Map<Class<? extends Packet>, IPacketHandler>> KNOWN_HANDLERS = AttributeKey.valueOf("KNOWN_HANDLERS");
 }
diff --git a/mcserver-manager/build.gradle b/mcserver-manager/build.gradle
index ac63d5a..479c2fa 100644
--- a/mcserver-manager/build.gradle
+++ b/mcserver-manager/build.gradle
@@ -19,7 +19,7 @@ jar {
 }
 
 ext {
-    nettyVersion = '4.1.9.Final'
+    nettyVersion = '4.0.23.Final'
 }
 
 dependencies {