diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 34a9bc6..021893c 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -405,6 +405,9 @@
 	override ENABLE_SVE_FOR_SWD	:= 0
 endif
 
+# SME2 defaults to disabled
+ENABLE_SME2_FOR_NS		:= 0
+
 SANITIZE_UB := off
 
 # For ARMv8.1 (AArch64) platforms, enabling this option selects the spinlock