diff --git a/plat/Makefile b/plat/Makefile
index 804c366..75be1f4 100644
--- a/plat/Makefile
+++ b/plat/Makefile
@@ -4,15 +4,15 @@ PLATDIR = ../plat
 BINDIR  = ../bin
 PLATMODULELIST = 8ecp aif bicc debug haepub iptrans isdn isup m2ua mgc mgcp mgc_v2 mtp3 pal public rtp sccp scf sip smpp snmp tcap xapp
 
+.PHONY: all $(PLATMODULELIST) clean
+
 # default all
 all: $(PLATMODULELIST)
 
 # plat module list
 $(PLATMODULELIST):
 	@echo "====================== make $@ ======================="
-	@cd $(PLATDIR)/$@ 
-	$(MAKE) clean 
-	$(MAKE)
+	@cd $(PLATDIR)/$@ && $(MAKE)
 	@if [ $@ = "iptrans" ]; then \
 		./generate_iptrans; \
 		cp -f ./iptrans $(BINDIR); \