diff --git a/flight/OpenPilot/UAVTalk/uavtalk.c b/flight/OpenPilot/UAVTalk/uavtalk.c
index dc8d15e64..a3ab07e0b 100644
--- a/flight/OpenPilot/UAVTalk/uavtalk.c
+++ b/flight/OpenPilot/UAVTalk/uavtalk.c
@@ -34,13 +34,13 @@
 // Private constants
 #define SYNC_VAL 0x3C
 #define TYPE_MASK 0xFC
-#define TYPE_VER 0x10
+#define TYPE_VER 0x20
 #define TYPE_OBJ (TYPE_VER | 0x00)
 #define TYPE_OBJ_REQ (TYPE_VER | 0x01)
 #define TYPE_OBJ_ACK (TYPE_VER | 0x02)
 #define TYPE_ACK (TYPE_VER | 0x03)
 
-#define HEADER_LENGTH 7 // type (1), object ID (4), instance ID (2, not used in single objects)
+#define HEADER_LENGTH 10 // sync(1), type (1), size (2), object ID (4), instance ID (2, not used in single objects)
 #define CHECKSUM_LENGTH 1
 #define MAX_PAYLOAD_LENGTH 256
 #define MAX_PACKET_LENGTH (HEADER_LENGTH+MAX_PAYLOAD_LENGTH+CHECKSUM_LENGTH)
diff --git a/ground/src/plugins/uavtalk/uavtalk.h b/ground/src/plugins/uavtalk/uavtalk.h
index a4c7e547d..40deac245 100644
--- a/ground/src/plugins/uavtalk/uavtalk.h
+++ b/ground/src/plugins/uavtalk/uavtalk.h
@@ -67,12 +67,12 @@ private slots:
 private:
     // Constants
     static const int TYPE_MASK = 0xFC;
-    static const int TYPE_VER = 0x10;
+    static const int TYPE_VER = 0x20;
     static const int TYPE_OBJ = (TYPE_VER | 0x00);
     static const int TYPE_OBJ_REQ = (TYPE_VER | 0x01);
     static const int TYPE_OBJ_ACK = (TYPE_VER | 0x02);
     static const int TYPE_ACK = (TYPE_VER | 0x03);
-    static const int HEADER_LENGTH = 7; // type (1), object ID (4), instance ID (2, not used in single objects)
+    static const int HEADER_LENGTH = 10; // sync(1), type (1), size(2), object ID (4), instance ID (2, not used in single objects)
     static const int CHECKSUM_LENGTH = 1;
     static const int MAX_PAYLOAD_LENGTH = 256;
     static const int MAX_PACKET_LENGTH = (HEADER_LENGTH+MAX_PAYLOAD_LENGTH+CHECKSUM_LENGTH);