diff --git a/plat/imx/imx8m/imx8mm/imx8mm_bl31_setup.c b/plat/imx/imx8m/imx8mm/imx8mm_bl31_setup.c
index 678f441..fcc5612 100644
--- a/plat/imx/imx8m/imx8mm/imx8mm_bl31_setup.c
+++ b/plat/imx/imx8m/imx8mm/imx8mm_bl31_setup.c
@@ -185,7 +185,7 @@
 }
 
 #define MAP_BL31_TOTAL										   \
-	MAP_REGION_FLAT(BL31_BASE, BL31_LIMIT - BL31_BASE, MT_MEMORY | MT_RW | MT_SECURE)
+	MAP_REGION_FLAT(BL31_BASE, BL31_SIZE, MT_MEMORY | MT_RW | MT_SECURE)
 #define MAP_BL31_RO										   \
 	MAP_REGION_FLAT(BL_CODE_BASE, BL_CODE_END - BL_CODE_BASE, MT_MEMORY | MT_RO | MT_SECURE)
 #define MAP_COHERENT_MEM									   \
diff --git a/plat/imx/imx8m/imx8mm/include/platform_def.h b/plat/imx/imx8m/imx8mm/include/platform_def.h
index 930372f..65749f3 100644
--- a/plat/imx/imx8m/imx8mm/include/platform_def.h
+++ b/plat/imx/imx8m/imx8mm/include/platform_def.h
@@ -7,6 +7,7 @@
 #include <arch.h>
 #include <common/tbbr/tbbr_img_def.h>
 #include <lib/utils_def.h>
+#include <plat/common/common_def.h>
 
 #define PLATFORM_LINKER_FORMAT		"elf64-littleaarch64"
 #define PLATFORM_LINKER_ARCH		aarch64
@@ -40,9 +41,9 @@
 
 #if defined(NEED_BL2)
 #define BL2_BASE			U(0x920000)
-#define BL2_LIMIT			U(0x940000)
+#define BL2_SIZE			SZ_128K
+#define BL2_LIMIT			(BL2_BASE + BL2_SIZE)
 #define BL31_BASE			U(0x900000)
-#define BL31_LIMIT			U(0x920000)
 #define IMX_FIP_BASE			U(0x40310000)
 #define IMX_FIP_SIZE			U(0x000300000)
 #define IMX_FIP_LIMIT			U(FIP_BASE + FIP_SIZE)
@@ -53,9 +54,11 @@
 #define PLAT_IMX8MM_BOOT_MMC_BASE	U(0x30B50000) /* SD */
 #else
 #define BL31_BASE			U(0x920000)
-#define BL31_LIMIT			U(0x940000)
 #endif
 
+#define BL31_SIZE			SZ_128K
+#define BL31_LIMIT			(BL31_BASE + BL31_SIZE)
+
 /* non-secure uboot base */
 #define PLAT_NS_IMAGE_OFFSET		U(0x40200000)
 #define PLAT_NS_IMAGE_SIZE		U(0x00200000)