diff --git a/engine/wscript b/engine/wscript
index e574ad17..911cde93 100644
--- a/engine/wscript
+++ b/engine/wscript
@@ -126,6 +126,9 @@ def configure(conf):
 	conf.define_cond('DBGHELP', conf.env.DEST_OS == 'win32')
 	conf.define_cond('PSAPI_VERSION', conf.env.DEST_OS == 'win32') # will be defined as 1
 
+	for refdll in conf.refdlls:
+		refdll.register_define(conf)
+
 def build(bld):
 	# public includes for renderers and utils use
 	bld(name = 'engine_includes', export_includes = '. common common/imagelib', use = 'filesystem_includes')