--- ZeroTierOne-1.2.4-orig/make-linux.mk
+++ ZeroTierOne-1.2.4/make-linux.mk
@@ -22,7 +22,7 @@
 # otherwise build into binary as done on Mac and Windows.
 OBJS+=osdep/PortMapper.o
 DEFS+=-DZT_USE_MINIUPNPC
-MINIUPNPC_IS_NEW_ENOUGH=$(shell grep -sqr '.*define.*MINIUPNPC_VERSION.*"2.."' /usr/include/miniupnpc/miniupnpc.h && echo 1)
+MINIUPNPC_IS_NEW_ENOUGH=$(shell grep -sqr '.*define.*MINIUPNPC_VERSION.*"2..*"' /usr/include/miniupnpc/miniupnpc.h && echo 1)
 ifeq ($(MINIUPNPC_IS_NEW_ENOUGH),1)
 	DEFS+=-DZT_USE_SYSTEM_MINIUPNPC
 	LDLIBS+=-lminiupnpc