diff --git a/plat/st/stm32mp1/stm32mp1_def.h b/plat/st/stm32mp1/stm32mp1_def.h
index 2ec9487674a2ed305b007e205903fe68d8ce56ce..94c4c5b38a1c4507459c8b569119174ed6deeb16 100644
--- a/plat/st/stm32mp1/stm32mp1_def.h
+++ b/plat/st/stm32mp1/stm32mp1_def.h
@@ -111,7 +111,7 @@ enum ddr_type {
 #endif
 
 /* DTB initialization value */
-#define STM32MP_DTB_SIZE		U(0x00004000)	/* 16Ko for DTB */
+#define STM32MP_DTB_SIZE		U(0x00005000)	/* 20Ko for DTB */
 
 #define STM32MP_DTB_BASE		(STM32MP_BL2_BASE - \
 					 STM32MP_DTB_SIZE)