diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index e794ae2..11ab798 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -761,6 +761,10 @@
    CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
    CPU and is still open.
 
+-  ``ERRATA_X2_2778471``: This applies errata 2778471 workaround to Cortex-X2
+   CPU. This needs to be enabled for revisions r0p0, r1p0, r2p0 and r2p1 of the
+   CPU and it is still open.
+
 For Cortex-X3, the following errata build flags are defined :
 
 - ``ERRATA_X3_2070301``: This applies errata 2070301 workaround to the Cortex-X3