diff --git a/plat/st/stm32mp1/stm32mp1_security.c b/plat/st/stm32mp1/stm32mp1_security.c
index ebf1587..0ad43e4 100644
--- a/plat/st/stm32mp1/stm32mp1_security.c
+++ b/plat/st/stm32mp1/stm32mp1_security.c
@@ -41,6 +41,7 @@
 			TZC_REGION_ACCESS_RDWR(STM32MP1_TZC_GPU_ID) |
 			TZC_REGION_ACCESS_RDWR(STM32MP1_TZC_LCD_ID) |
 			TZC_REGION_ACCESS_RDWR(STM32MP1_TZC_MDMA_ID) |
+			TZC_REGION_ACCESS_RDWR(STM32MP1_TZC_M4_ID) |
 			TZC_REGION_ACCESS_RDWR(STM32MP1_TZC_DMA_ID) |
 			TZC_REGION_ACCESS_RDWR(STM32MP1_TZC_USB_HOST_ID) |
 			TZC_REGION_ACCESS_RDWR(STM32MP1_TZC_USB_OTG_ID) |