diff --git a/src/comms/java/comms/ConstructingDeserializer.java b/src/comms/java/comms/ConstructingDeserializer.java
index c6407976..5b49ecdb 100644
--- a/src/comms/java/comms/ConstructingDeserializer.java
+++ b/src/comms/java/comms/ConstructingDeserializer.java
@@ -39,7 +39,7 @@ public enum ConstructingDeserializer implements MessageDeserializer {
     }
 
     @Override
-    public iMessage deserialize(DataInputStream in) throws IOException {
+    public synchronized iMessage deserialize(DataInputStream in) throws IOException {
         int type = ((int) in.readByte()) & 0xff;
         try {
             return MSGS.get(type).getConstructor(DataInputStream.class).newInstance(in);
diff --git a/src/comms/java/comms/SerializedConnection.java b/src/comms/java/comms/SerializedConnection.java
index 0952854d..c4191194 100644
--- a/src/comms/java/comms/SerializedConnection.java
+++ b/src/comms/java/comms/SerializedConnection.java
@@ -35,7 +35,7 @@ public class SerializedConnection implements IConnection {
     }
 
     @Override
-    public void sendMessage(iMessage message) throws IOException {
+    public synchronized void sendMessage(iMessage message) throws IOException {
         message.writeHeader(out);
         message.write(out);
     }