diff --git a/gprs_bssgp_pcu.h b/gprs_bssgp_pcu.h
index bc32173..0f8dd83 100644
--- a/gprs_bssgp_pcu.h
+++ b/gprs_bssgp_pcu.h
@@ -42,7 +42,7 @@
 #define NSEI 3
 
 #define QOS_PROFILE 0
-#define BSSGP_HDR_LEN 20
+#define BSSGP_HDR_LEN 53
 #define NS_HDR_LEN 4
 #define MAX_LEN_PDU 60
 #define IE_PDU 14