diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst
index 65f6adb..a89305b 100644
--- a/docs/cpu-specific-build-macros.rst
+++ b/docs/cpu-specific-build-macros.rst
@@ -24,6 +24,12 @@
    with the recommendation in the spec regarding workaround discovery.
    Defaults to 1.
 
+-  ``WORKAROUND_CVE_2018_3639``: Enables the security workaround for
+   `CVE-2018-3639`_. Defaults to 1. The TF-A project recommends to keep
+   the default value of 1 even on platforms that are unaffected by
+   CVE-2018-3639, in order to comply with the recommendation in the spec
+   regarding workaround discovery.
+
 CPU Errata Workarounds
 ----------------------