diff --git a/common/KVMFR.h b/common/KVMFR.h
index 716bf108..dce4c68f 100644
--- a/common/KVMFR.h
+++ b/common/KVMFR.h
@@ -66,8 +66,9 @@ typedef struct KVMFRFrame
 }
 KVMFRFrame;
 
-#define KVMFR_HEADER_FLAG_FRAME  1 // frame update available
-#define KVMFR_HEADER_FLAG_CURSOR 2 // cursor update available
+#define KVMFR_HEADER_FLAG_FRAME   1 // frame update available
+#define KVMFR_HEADER_FLAG_CURSOR  2 // cursor update available
+#define KVMFR_HEADER_FLAG_RESTART 4 // restart signal from client
 
 typedef struct KVMFRHeader
 {