diff --git a/board/esd/ar405/flash.c b/board/esd/ar405/flash.c
index 4fa6b27..3a644f9 100644
--- a/board/esd/ar405/flash.c
+++ b/board/esd/ar405/flash.c
@@ -94,7 +94,7 @@
 
 	/* monitor protection ON by default */
 	(void)flash_protect(FLAG_PROTECT_SET,
-			    base_b0+size_b0-CFG_MONITOR_LEN,
+			    base_b0+size_b0-monitor_flash_len,
 			    base_b0+size_b0-1,
 			    &flash_info[0]);
 
@@ -106,12 +106,12 @@
 
 		/* monitor protection ON by default */
 		(void)flash_protect(FLAG_PROTECT_SET,
-				    base_b1+size_b1-CFG_MONITOR_LEN,
+				    base_b1+size_b1-monitor_flash_len,
 				    base_b1+size_b1-1,
 				    &flash_info[1]);
                 /* monitor protection OFF by default (one is enough) */
                 (void)flash_protect(FLAG_PROTECT_CLEAR,
-                                    base_b0+size_b0-CFG_MONITOR_LEN,
+                                    base_b0+size_b0-monitor_flash_len,
                                     base_b0+size_b0-1,
                                     &flash_info[0]);
 	} else {