diff --git a/3rdParty/Makefile.all-in-one-mruby b/3rdParty/Makefile.all-in-one-mruby
index e816ef6df0..78fce1c137 100644
--- a/3rdParty/Makefile.all-in-one-mruby
+++ b/3rdParty/Makefile.all-in-one-mruby
@@ -19,7 +19,7 @@ BUILT_SOURCES += @MRUBY_LIBS@
 	@echo "--------------------------------------------------------------------------------"
 	@echo
 
-	cd @top_srcdir@/3rdParty/mruby && CC="" CFLAGS="" $(MAKE) -j1
+	cd @top_srcdir@/3rdParty/mruby && $(MAKE) -j1
 
 	touch @srcdir@/.mruby-build-@TRI_BITS@