diff --git a/docs/glossary.rst b/docs/glossary.rst
index abacc9e..f19897c 100644
--- a/docs/glossary.rst
+++ b/docs/glossary.rst
@@ -100,6 +100,9 @@
    GIC
       Generic Interrupt Controller
 
+   HES
+      Arm CCA Hardware Enforced Security
+
    ISA
       Instruction Set Architecture
 
@@ -165,6 +168,9 @@
    ROT
       Root of Trust
 
+   RSE
+      Runtime Security Engine
+
    SCMI
       System Control and Management Interface