diff --git a/docs/cpu-specific-build-macros.rst b/docs/cpu-specific-build-macros.rst
index a89305b..c11f640 100644
--- a/docs/cpu-specific-build-macros.rst
+++ b/docs/cpu-specific-build-macros.rst
@@ -30,6 +30,11 @@
    CVE-2018-3639, in order to comply with the recommendation in the spec
    regarding workaround discovery.
 
+-  ``DYNAMIC_WORKAROUND_CVE_2018_3639``: Enables dynamic mitigation for
+   `CVE-2018-3639`_. This build option should be set to 1 if the target
+   platform contains at least 1 CPU that requires dynamic mitigation.
+   Defaults to 0.
+
 CPU Errata Workarounds
 ----------------------