diff --git a/plat/rockchip/rk3399/include/platform_def.h b/plat/rockchip/rk3399/include/platform_def.h
index f7da0e7..5f04db9 100644
--- a/plat/rockchip/rk3399/include/platform_def.h
+++ b/plat/rockchip/rk3399/include/platform_def.h
@@ -109,7 +109,7 @@
  ******************************************************************************/
 #define ADDR_SPACE_SIZE		(1ull << 32)
 #define MAX_XLAT_TABLES		20
-#define MAX_MMAP_REGIONS	16
+#define MAX_MMAP_REGIONS	20
 
 /*******************************************************************************
  * Declarations and constants to access the mailboxes safely. Each mailbox is