diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 9273469..0127607 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -65,6 +65,9 @@
 # Debug build
 DEBUG				:= 0
 
+# By default disable authenticated decryption support.
+DECRYPTION_SUPPORT		:= none
+
 # Build platform
 DEFAULT_PLAT			:= fvp