diff --git a/boards/mulle/Makefile.include b/boards/mulle/Makefile.include
index 49392d7ceec17dd9da4da31ea187fffab88fde78..abfaf433a07b96ea1b229e338795c2695cbfb65d 100644
--- a/boards/mulle/Makefile.include
+++ b/boards/mulle/Makefile.include
@@ -82,7 +82,11 @@ ifeq ($(PORT),)
       PORT := $(shell $(RIOTBASE)/dist/tools/usb-serial/find-tty.sh)
   endif
   else ifeq ($(OS),Darwin)
-    PORT := $(firstword $(sort $(wildcard /dev/tty.usbserial*)))
+    ifneq ($(PROGRAMMER_SERIAL),)
+      PORT := /dev/tty.usbserial-$(PROGRAMMER_SERIAL)B
+    else
+      PORT := $(firstword $(sort $(wildcard /dev/tty.usbserial*)))
+    endif
   endif
 endif
 ifeq ($(PORT),)