diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index a5633e9..ac03806 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -714,6 +714,13 @@
 
    This option defaults to 0.
 
+-  ``MARCH_DIRECTIVE``: used to pass a -march option from the platform build
+   options to the compiler. An example usage:
+
+   .. code:: make
+
+      MARCH_DIRECTIVE := -march=armv8.5-a
+
 -  ``NON_TRUSTED_WORLD_KEY``: This option is used when ``GENERATE_COT=1``. It
    specifies the file that contains the Non-Trusted World private key in PEM
    format. If ``SAVE_KEYS=1``, this file name will be used to save the key.