diff --git a/gprs_bssgp_pcu.h b/gprs_bssgp_pcu.h
index 6175917..bc32173 100644
--- a/gprs_bssgp_pcu.h
+++ b/gprs_bssgp_pcu.h
@@ -46,7 +46,7 @@
 #define NS_HDR_LEN 4
 #define MAX_LEN_PDU 60
 #define IE_PDU 14
-#define BLOCK_DATA_LEN 19
+#define BLOCK_DATA_LEN 20
 #define BLOCK_LEN 23
 
 #define CELL_ID 3