diff --git a/lib/connector/meshcore_protocol.dart b/lib/connector/meshcore_protocol.dart
index 396d78b3..02e75db3 100644
--- a/lib/connector/meshcore_protocol.dart
+++ b/lib/connector/meshcore_protocol.dart
@@ -320,7 +320,7 @@ const int maxPathSize = 64;
 const int pathHashSize = 1;
 const int maxNameSize = 32;
 const int maxFrameSize = 172;
-const int appProtocolVersion = 3;
+const int appProtocolVersion = 4;
 // Matches firmware MAX_TEXT_LEN (10 * CIPHER_BLOCK_SIZE).
 const int maxTextPayloadBytes = 160;
 const int _sendTextMsgOverheadBytes =