diff --git a/Makefile b/Makefile
index 907ae21..ef01fef 100644
--- a/Makefile
+++ b/Makefile
@@ -312,6 +312,10 @@
 # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105523
 TF_CFLAGS		+= 	$(call cc_option, --param=min-pagesize=0)
 
+ifeq ($(HARDEN_SLS), 1)
+        TF_CFLAGS_aarch64       +=      $(call cc_option, -mharden-sls=all)
+endif
+
 else
 # using clang
 WARNINGS	+=		-Wshift-overflow -Wshift-sign-overflow \
@@ -1179,6 +1183,7 @@
 	GENERATE_COT \
 	GICV2_G0_FOR_EL3 \
 	HANDLE_EA_EL3_FIRST_NS \
+	HARDEN_SLS \
 	HW_ASSISTED_COHERENCY \
 	MEASURED_BOOT \
 	DRTM_SUPPORT \