diff --git a/src/main/java/com/github/manevolent/ts3j/protocol/socket/client/AbstractTeamspeakClientSocket.java b/src/main/java/com/github/manevolent/ts3j/protocol/socket/client/AbstractTeamspeakClientSocket.java
index 35bd662..59bb55e 100644
--- a/src/main/java/com/github/manevolent/ts3j/protocol/socket/client/AbstractTeamspeakClientSocket.java
+++ b/src/main/java/com/github/manevolent/ts3j/protocol/socket/client/AbstractTeamspeakClientSocket.java
@@ -75,7 +75,8 @@ public abstract class AbstractTeamspeakClientSocket
 
     private Identity identity = null;
     private ClientConnectionState connectionState = null;
-    private PacketTransformation transformation = new InitPacketTransformation();
+    private final PacketTransformation initTransformation = new InitPacketTransformation();
+    private PacketTransformation transformation = initTransformation;
     private PacketHandler handler;
 
     private int clientId = 0;
@@ -543,15 +544,11 @@ public abstract class AbstractTeamspeakClientSocket
                     + " generation=" + networkPacket.getHeader().getGeneration());
 
             PacketTransformation transformation = getTransformation();
+            int dataLen = networkPacket.getDatagram().getLength() - networkPacket.getHeader().getSize();
 
             try {
                 packetBuffer = ByteBuffer.wrap(
-                        transformation.decrypt(
-                                networkPacket.getHeader(),
-                                packetBuffer,
-                                networkPacket.getDatagram().getLength() -
-                                        networkPacket.getHeader().getSize()
-                        )
+                        decrypt(transformation, networkPacket.getHeader(), packetBuffer, dataLen)
                 ).order(ByteOrder.BIG_ENDIAN);
             } catch (InvalidCipherTextException e) {
                 throw new IOException(
@@ -604,6 +601,20 @@ public abstract class AbstractTeamspeakClientSocket
         return packet;
     }
 
+    /**
+     * Decrypts with the session key, falling back to the handshake key: the server encrypts initivexpand2 with
+     * the latter, so its retransmits (sent when our ACK was lost) still arrive under it after the key switch.
+     */
+    private byte[] decrypt(PacketTransformation transformation, PacketHeader header, ByteBuffer buffer, int dataLen)
+            throws InvalidCipherTextException {
+        try {
+            return transformation.decrypt(header, buffer, dataLen);
+        } catch (InvalidCipherTextException e) {
+            if (transformation instanceof InitPacketTransformation || header.getGeneration() != 0) throw e;
+            return initTransformation.decrypt(header, buffer, dataLen);
+        }
+    }
+
     @Override
     public Packet readPacket() throws
             IOException,