diff --git a/core/arch/arm/plat-stm32mp1/conf.mk b/core/arch/arm/plat-stm32mp1/conf.mk
index 058199a489c..c488c588741 100644
--- a/core/arch/arm/plat-stm32mp1/conf.mk
+++ b/core/arch/arm/plat-stm32mp1/conf.mk
@@ -129,7 +129,7 @@ $(call force,CFG_SECONDARY_INIT_CNTFRQ,y)
 $(call force,CFG_STM32MP1_SHARED_RESOURCES,y)
 $(call force,CFG_STM32_SAES,n)
 $(call force,CFG_STM32MP15_CLK,y)
-CFG_CORE_RESERVED_SHM ?= y
+CFG_CORE_RESERVED_SHM ?= n
 CFG_EXTERNAL_DT ?= y
 CFG_STM32_BSEC_SIP ?= y
 CFG_TEE_CORE_NB_CORE ?= 2