diff --git a/r5dev/common/protocol.h b/r5dev/common/protocol.h
index deadc29c..5225f389 100644
--- a/r5dev/common/protocol.h
+++ b/r5dev/common/protocol.h
@@ -4,6 +4,10 @@
  * _protocol.h
  *-----------------------------------------------------------------------------*/
 
+ // Max number of history commands to send ( 2 by default ) in case of dropped packets
+#define NUM_BACKUP_COMMAND_BITS		4 // Originally 3 bits.
+#define MAX_BACKUP_COMMANDS			((1 << NUM_BACKUP_COMMAND_BITS)-1) // 15 in R5; see 'CL_Move'.
+
 enum class SIGNONSTATE : int
 {
 	SIGNONSTATE_NONE         = 0, // no state yet; about to connect.