diff --git a/plat/st/stm32mp1/platform.mk b/plat/st/stm32mp1/platform.mk
index 194672ee5..ddc528925 100644
--- a/plat/st/stm32mp1/platform.mk
+++ b/plat/st/stm32mp1/platform.mk
@@ -62,7 +62,7 @@ STM32_HEADER_VERSION_MAJOR:=	1
 STM32_HEADER_VERSION_MINOR:=	0
 
 # Add OP-TEE reserved shared memory area in mapping
-STM32MP15_OPTEE_RSV_SHM	:=	1
+STM32MP15_OPTEE_RSV_SHM	:=	0
 $(eval $(call add_defines,STM32MP15_OPTEE_RSV_SHM))
 
 STM32MP_CRYPTO_ROM_LIB :=	1