diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 578bd59..f69a73e 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -79,6 +79,10 @@
 # Disable the generation of the binary image (ELF only).
 DISABLE_BIN_GENERATION		:= 0
 
+# Disable MTPMU if FEAT_MTPMU is supported. Default is 0 to keep backwards
+# compatibility.
+DISABLE_MTPMU			:= 0
+
 # Enable capability to disable authentication dynamically. Only meant for
 # development platforms.
 DYN_DISABLE_AUTH		:= 0