diff --git a/docs/system/arm/emulation.rst b/docs/system/arm/emulation.rst
index 3e95bba0d2..49cc3e8340 100644
--- a/docs/system/arm/emulation.rst
+++ b/docs/system/arm/emulation.rst
@@ -29,6 +29,7 @@ the following architecture extensions:
 - FEAT_FRINTTS (Floating-point to integer instructions)
 - FEAT_FlagM (Flag manipulation instructions v2)
 - FEAT_FlagM2 (Enhancements to flag manipulation instructions)
+- FEAT_HCX (Support for the HCRX_EL2 register)
 - FEAT_HPDS (Hierarchical permission disables)
 - FEAT_I8MM (AArch64 Int8 matrix multiplication instructions)
 - FEAT_IDST (ID space trap handling)