diff --git a/bl31/bl31.mk b/bl31/bl31.mk
index bff9653..066c701 100644
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@@ -24,6 +24,7 @@
 				bl31/bl31_context_mgmt.c			\
 				common/runtime_svc.c				\
 				lib/aarch64/setjmp.S				\
+				lib/cpus/aarch64/dsu_helpers.S			\
 				plat/common/aarch64/platform_mp_stack.S		\
 				services/arm_arch_svc/arm_arch_svc_setup.c	\
 				services/std_svc/std_svc_setup.c		\