diff --git a/docs/design/cpu-specific-build-macros.rst b/docs/design/cpu-specific-build-macros.rst
index 3485dc9..652c142 100644
--- a/docs/design/cpu-specific-build-macros.rst
+++ b/docs/design/cpu-specific-build-macros.rst
@@ -791,6 +791,10 @@
   CPU. This needs to be enabled only for revisions r0p0, r1p0 and r1p1 of the
   CPU, it is still open.
 
+- ``ERRATA_X3_2641945``: This applies errata 2641945 workaround to Cortex-X3
+  CPU. This needs to be enabled only for revisions r0p0 and r1p0 of the CPU.
+  It is fixed in r1p1.
+
 - ``ERRATA_X3_2742421``: This applies errata 2742421 workaround to
   Cortex-X3 CPU. This needs to be enabled only for revisions r0p0, r1p0 and
   r1p1. It is fixed in r1p2.