diff --git a/src/smblib/smbdefs.h b/src/smblib/smbdefs.h
index c7f6de245e14ad6c72dc747f84dcb72724635d70..41bb3462fadda6fcc8541f3d66b5ebb1fbe0d7d1 100644
--- a/src/smblib/smbdefs.h
+++ b/src/smblib/smbdefs.h
@@ -131,6 +131,7 @@
 #define SMB_ERR_HDR_FIELD	-105		/* Missing header field */
 #define SMB_ERR_NOT_FOUND	-110		/* Item not found */
 #define SMB_ERR_DAT_OFFSET	-120		/* Invalid data offset (>2GB) */
+#define SMB_ERR_DAT_LEN		-121		/* Invalid data length (>2GB) */
 #define SMB_ERR_OPEN		-200		/* File open error */
 #define SMB_ERR_SEEK		-201		/* File seek/setpos error */
 #define SMB_ERR_LOCK		-202		/* File lock error */