diff --git a/make_helpers/build_macros.mk b/make_helpers/build_macros.mk
index 5171ff0..19b88ad 100644
--- a/make_helpers/build_macros.mk
+++ b/make_helpers/build_macros.mk
@@ -68,6 +68,13 @@
     DEFINES			+=	-D$(1)$(if $(value $(1)),=$(value $(1)),)
 endef
 
+# Convenience function for adding build definitions
+# $(eval $(call add_define_val,FOO,BAR)) will have:
+# -DFOO=BAR
+define add_define_val
+    DEFINES			+=	-D$(1)=$(2)
+endef
+
 # Convenience function for verifying option has a boolean value
 # $(eval $(call assert_boolean,FOO)) will assert FOO is 0 or 1
 define assert_boolean