diff --git a/ArduCopter/version.h b/ArduCopter/version.h
index 17fe7cadb5..02d04478ce 100644
--- a/ArduCopter/version.h
+++ b/ArduCopter/version.h
@@ -6,12 +6,12 @@
 
 #include "ap_version.h"
 
-#define THISFIRMWARE "ArduCopter V3.6.5"
+#define THISFIRMWARE "ArduCopter V3.6.6-rc1"
 
 // the following line is parsed by the autotest scripts
-#define FIRMWARE_VERSION 3,6,5,FIRMWARE_VERSION_TYPE_OFFICIAL
+#define FIRMWARE_VERSION 3,6,6,FIRMWARE_VERSION_TYPE_RC
 
 #define FW_MAJOR 3
 #define FW_MINOR 6
-#define FW_PATCH 5
-#define FW_TYPE FIRMWARE_VERSION_TYPE_OFFICIAL
+#define FW_PATCH 6
+#define FW_TYPE FIRMWARE_VERSION_TYPE_RC