diff --git a/src/org/traccar/protocol/WatchFrameDecoder.java b/src/org/traccar/protocol/WatchFrameDecoder.java
index 826a8b4d..c1a1c868 100644
--- a/src/org/traccar/protocol/WatchFrameDecoder.java
+++ b/src/org/traccar/protocol/WatchFrameDecoder.java
@@ -21,7 +21,6 @@ import org.jboss.netty.channel.Channel;
 import org.jboss.netty.channel.ChannelHandlerContext;
 import org.jboss.netty.handler.codec.frame.FrameDecoder;

-import java.nio.charset.StandardCharsets;

 public class WatchFrameDecoder extends FrameDecoder {

@@ -34,11 +33,9 @@ public class WatchFrameDecoder extends FrameDecoder {
         if (buf.readableBytes() >= MESSAGE_HEADER) {
             ChannelBuffer lengthBuffer = ChannelBuffers.dynamicBuffer();
             buf.getBytes(buf.readerIndex() + MESSAGE_HEADER - 4 - 1, lengthBuffer, 4);
-            int length = Integer.parseInt(lengthBuffer.toString(StandardCharsets.US_ASCII), 16) + MESSAGE_HEADER + 1;
-            if (buf.readableBytes() >= length) {
+            if (buf.readableBytes() >= 10) {
                 ChannelBuffer frame = ChannelBuffers.dynamicBuffer();
-                int endIndex = buf.readerIndex() + length;
-                while (buf.readerIndex() < endIndex) {
+                while (true) {
                     byte b = buf.readByte();
                     if (b == 0x7D) {
                         switch (buf.readByte()) {
@@ -63,6 +60,9 @@ public class WatchFrameDecoder extends FrameDecoder {
                     } else {
                         frame.writeByte(b);
                     }
+                    if (b == 0x5D) { // await the terminating ']' character;
+                        break;
+                    }
                 }
                 return frame;
             }