diff --git a/ArmPkg/Include/Library/ArmLib.h b/ArmPkg/Include/Library/ArmLib.h
index 3a3991c231..c1d4009aa5 100644
--- a/ArmPkg/Include/Library/ArmLib.h
+++ b/ArmPkg/Include/Library/ArmLib.h
@@ -76,6 +76,7 @@ typedef enum {
   ARM_PROCESSOR_MODE_IRQ        = 0x12,
   ARM_PROCESSOR_MODE_SUPERVISOR = 0x13,
   ARM_PROCESSOR_MODE_ABORT      = 0x17,
+  ARM_PROCESSOR_MODE_HYP        = 0x1A,
   ARM_PROCESSOR_MODE_UNDEFINED  = 0x1B,
   ARM_PROCESSOR_MODE_SYSTEM     = 0x1F,
   ARM_PROCESSOR_MODE_MASK       = 0x1F