diff --git a/board/netstal/mcu25/Makefile b/board/netstal/mcu25/Makefile
index cd62642..a983de9 100644
--- a/board/netstal/mcu25/Makefile
+++ b/board/netstal/mcu25/Makefile
@@ -23,7 +23,7 @@
 $(shell mkdir -p $(obj)../common)
 endif
 
-LIB	= $(obj)lib$(BOARD).a
+LIB	= $(obj)lib$(BOARD).o
 
 COBJS	= $(BOARD).o \
 	../common/fixed_sdram.o \
@@ -33,7 +33,7 @@
 OBJS	:= $(addprefix $(obj),$(COBJS))
 
 $(LIB):	$(OBJS)
-	$(AR) $(ARFLAGS) $@ $^
+	$(call cmd_link_o_target, $^)
 
 clean:
 	rm -f $(OBJS)