diff --git a/ctree.h b/ctree.h
index d6467f6f..d9209783 100644
--- a/ctree.h
+++ b/ctree.h
@@ -27,7 +27,7 @@
 
 struct btrfs_root;
 struct btrfs_trans_handle;
-#define BTRFS_MAGIC "_B5RfS_M"
+#define BTRFS_MAGIC "_B6RfS_M"
 
 #define BTRFS_MAX_LEVEL 8