diff --git a/docs/plat/stm32mp1.rst b/docs/plat/stm32mp1.rst
index 17f7a86..af302c6 100644
--- a/docs/plat/stm32mp1.rst
+++ b/docs/plat/stm32mp1.rst
@@ -181,6 +181,7 @@
 .. code:: bash
 
     make CROSS_COMPILE=arm-none-eabi- PLAT=stm32mp1 ARCH=aarch32 ARM_ARCH_MAJOR=7 \
+        AARCH32_SP=optee \
         DTB_FILE_NAME=stm32mp157c-ev1.dtb \
         BL33=<u-boot_directory>/u-boot-nodtb.bin \
         BL33_CFG=<u-boot_directory>/u-boot.dtb \