diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 949845a..a9d6e37 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -325,6 +325,10 @@
 
 For Neoverse V1, the following errata build flags are defined :
 
+-  ``ERRATA_V1_1774420``: This applies errata 1774420 workaround to Neoverse-V1
+   CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
+   in r1p1.
+
 -  ``ERRATA_V1_1791573``: This applies errata 1791573 workaround to Neoverse-V1
    CPU. This needs to be enabled only for revisions r0p0 and r1p0, it is fixed
    in r1p1.