diff --git a/docs/firmware-design.rst b/docs/firmware-design.rst
index 9e206dc..52520ea 100644
--- a/docs/firmware-design.rst
+++ b/docs/firmware-design.rst
@@ -2521,7 +2521,7 @@
 controlling them.
 
 In general, and unless individually mentioned, the build options
-``ARM_ARCH_MAJOR`` and ``ARM_ARCH_MINOR`` selects the Architecture Extension to
+``ARM_ARCH_MAJOR`` and ``ARM_ARCH_MINOR`` select the Architecture Extension to
 target when building TF-A. Subsequent Arm Architecture Extensions are backward
 compatible with previous versions.
 
@@ -2570,6 +2570,10 @@
    ``CTX_INCLUDE_PAUTH_REGS`` to 1. This enables pointer authentication in BL1,
    BL2, BL31, and the TSP if it is used.
 
+   If ``ARM_ARCH_MAJOR == 8`` and ``ARM_ARCH_MINOR >= 3`` the code footprint of
+   enabling PAuth is lower because the compiler will use the optimized
+   PAuth instructions rather than the backwards-compatible ones.
+
 Armv7-A
 ~~~~~~~