diff --git a/bl31/bl31.mk b/bl31/bl31.mk
index 0948e94..735d1fc 100644
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@@ -89,10 +89,16 @@
 CRASH_REPORTING		:=	$(DEBUG)
 endif
 
-$(eval $(call assert_boolean,CRASH_REPORTING))
-$(eval $(call assert_boolean,EL3_EXCEPTION_HANDLING))
-$(eval $(call assert_boolean,SDEI_SUPPORT))
+$(eval $(call assert_booleans,\
+    $(sort \
+	CRASH_REPORTING \
+	EL3_EXCEPTION_HANDLING \
+	SDEI_SUPPORT \
+)))
 
-$(eval $(call add_define,CRASH_REPORTING))
-$(eval $(call add_define,EL3_EXCEPTION_HANDLING))
-$(eval $(call add_define,SDEI_SUPPORT))
+$(eval $(call add_defines,\
+    $(sort \
+        CRASH_REPORTING \
+        EL3_EXCEPTION_HANDLING \
+        SDEI_SUPPORT \
+)))