diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 590a800..608e963 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -293,3 +293,6 @@
 # than Armv8.5-A
 # By default it is set to "no"
 SUPPORT_STACK_MEMTAG		:= no
+
+# Select workaround for AT speculative behaviour.
+ERRATA_SPECULATIVE_AT           := 0