diff --git a/ports/unix/Makefile b/ports/unix/Makefile
index 4790e0eacf..5141beff4c 100644
--- a/ports/unix/Makefile
+++ b/ports/unix/Makefile
@@ -296,9 +296,10 @@ include $(TOP)/py/mkrules.mk
 
 .PHONY: test test_full
 
+TEST_EXTRA ?=
 test: $(PROG) $(TOP)/tests/run-tests.py
 	$(eval DIRNAME=ports/$(notdir $(CURDIR)))
-	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/$(PROG) ./run-tests.py
+	cd $(TOP)/tests && MICROPY_MICROPYTHON=../$(DIRNAME)/$(PROG) ./run-tests.py $(TEST_EXTRA)
 
 test_full: $(PROG) $(TOP)/tests/run-tests.py
 	$(eval DIRNAME=ports/$(notdir $(CURDIR)))