diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 72bd01c..ed0e335 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -822,6 +822,10 @@
   feature is enabled and can assist the Kernel in the process of
   mitigation of the erratum.
 
+-  ``ERRATA_X4_2740089``: This applies errata 2740089 workaround to Cortex-X4
+   CPU. This needs to be enabled for revisions r0p0 and r0p1. It is fixed
+   in r0p2.
+
 For Cortex-A510, the following errata build flags are defined :
 
 -  ``ERRATA_A510_1922240``: This applies errata 1922240 workaround to