diff --git a/Makefile b/Makefile
index ec6f885..a110964 100644
--- a/Makefile
+++ b/Makefile
@@ -1185,6 +1185,8 @@
 
 # Expand build macros for the different images
 ifeq (${NEED_BL1},yes)
+BL1_SOURCES := $(sort ${BL1_SOURCES})
+
 $(eval $(call MAKE_BL,bl1))
 endif