--- Makefile.orig	2024-01-04 00:43:45 UTC
+++ Makefile
@@ -147,7 +147,6 @@ TESTIGDDESCPARSE += $(BUILD)/minissdpc.o
 LIBOBJS += $(BUILD)/minissdpc.o
 endif
 
-LIBDIR ?= lib
 # install directories
 ifeq ($(strip $(PREFIX)),)
 INSTALLPREFIX ?= /usr
@@ -155,7 +154,7 @@ else
 INSTALLPREFIX ?= $(PREFIX)
 endif
 INSTALLDIRINC = $(INSTALLPREFIX)/include/miniupnpc
-INSTALLDIRLIB = $(INSTALLPREFIX)/$(LIBDIR)
+INSTALLDIRLIB = $(INSTALLPREFIX)/lib
 INSTALLDIRBIN = $(INSTALLPREFIX)/bin
 INSTALLDIRMAN = $(INSTALLPREFIX)/share/man
 PKGCONFIGDIR = $(INSTALLDIRLIB)/pkgconfig
@@ -242,7 +241,7 @@ distclean: clean
 
 updateversion:	include/miniupnpc.h
 	cp $< $<.bak
-	sed 's/\(.*MINIUPNPC_API_VERSION\s\+\)[0-9]\+/\1$(APIVERSION)/' < $<.bak > $<
+	sed -E 's/(.*MINIUPNPC_API_VERSION[[:space:]]+)[0-9]+/\1$(APIVERSION)/' < $<.bak > $<
 
 install:	updateversion $(FILESTOINSTALL)
 	$(INSTALL) -d $(DESTDIR)$(INSTALLDIRINC)