diff --git a/ArduCopter/version.h b/ArduCopter/version.h
index c615c41cb6..4424cf394b 100644
--- a/ArduCopter/version.h
+++ b/ArduCopter/version.h
@@ -6,7 +6,7 @@
 
 #include "ap_version.h"
 
-#define THISFIRMWARE "ArduCopter V4.0.0-rc3"
+#define THISFIRMWARE "ArduCopter V4.0.0-rc4"
 
 // the following line is parsed by the autotest scripts
 #define FIRMWARE_VERSION 4,0,0,FIRMWARE_VERSION_TYPE_RC