diff --git a/fs_defs.h b/fs_defs.h
index 6f38785..1dc880b 100644
--- a/fs_defs.h
+++ b/fs_defs.h
@@ -17,6 +17,7 @@ extern "C" {
 
 #define FS_STATUS_OK                    0
 #define FS_STATUS_EOF                   -2
+#define FS_STATUS_FATAL_ERROR           -0x400
 #define FS_RET_UNSUPPORTED_CMD          0x0400
 #define FS_RET_NO_ERROR                 0x0000
 #define FS_RET_ALL_ERROR                (u32)(-1)