diff --git a/board/gth/flash.c b/board/gth/flash.c
index 562a349..c8b56fb 100644
--- a/board/gth/flash.c
+++ b/board/gth/flash.c
@@ -102,7 +102,7 @@
 	  /* monitor protection ON by default */
 	  (void)flash_protect(FLAG_PROTECT_SET,
 			    CFG_MONITOR_BASE,
-			    CFG_MONITOR_BASE+CFG_MONITOR_LEN-1,
+			    CFG_MONITOR_BASE+monitor_flash_len-1,
 			    &flash_info[0]);
 #endif
 
@@ -121,7 +121,7 @@
 		/* monitor protection ON by default */
 		(void)flash_protect(FLAG_PROTECT_SET,
 				    CFG_MONITOR_BASE,
-				    CFG_MONITOR_BASE+CFG_MONITOR_LEN-1,
+				    CFG_MONITOR_BASE+monitor_flash_len-1,
 				    &flash_info[1]);
 #endif
 	}