diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 2e3fe74..b053647 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -331,6 +331,10 @@
   Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
   it is still open.
 
+- ``ERRATA_A78C_2242638`` : This applies errata 2242638 workaround to
+  Cortex-A78C CPU. This needs to be enabled for revisions r0p1, r0p2 and
+  it is still open.
+
 For Cortex-X1 CPU, the following errata build flags are defined:
 
 - ``ERRATA_X1_1821534`` : This applies errata 1821534 workaround to Cortex-X1