diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 9db29e6..53b54b8 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -317,6 +317,10 @@
    CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
    it is still open.
 
+-  ``ERRATA_A78_2742426``: This applies erratum 2742426 workaround to Cortex-A78
+   CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1 and r1p2 and
+   it is still open.
+
 -  ``ERRATA_A78_2772019``: This applies errata 2772019 workaround to Cortex-A78
    CPU. This needs to be enabled for revisions r0p0, r1p0, r1p1, and r1p2, and
    it is still open.