diff --git a/plat/st/stm32mp1/stm32mp1_def.h b/plat/st/stm32mp1/stm32mp1_def.h
index 291342e..ab3ef17 100644
--- a/plat/st/stm32mp1/stm32mp1_def.h
+++ b/plat/st/stm32mp1/stm32mp1_def.h
@@ -102,6 +102,8 @@
 #define STM32MP_PARAM_LOAD_SIZE		U(0x00002400)	/* 9 KB for param */
 /* 256 Octets reserved for header */
 #define STM32MP_HEADER_SIZE		U(0x00000100)
+/* round_up(STM32MP_PARAM_LOAD_SIZE + STM32MP_HEADER_SIZE, PAGE_SIZE) */
+#define STM32MP_HEADER_RESERVED_SIZE	U(0x3000)
 
 #define STM32MP_BINARY_BASE		(STM32MP_SEC_SYSRAM_BASE +	\
 					 STM32MP_PARAM_LOAD_SIZE +	\