diff -Naur unzip60.orig/unix/Makefile unzip60/unix/Makefile
--- unzip60.orig/unix/Makefile	2009-01-18 14:41:18.000000000 +0000
+++ unzip60/unix/Makefile	2019-09-04 16:29:06.835398649 +0000
@@ -121,7 +121,7 @@
 INSTALL_D = mkdir -p
 # on some systems, manext=l and MANDIR=/usr/man/man$(manext) may be appropriate
 manext = 1
-prefix = /usr/local
+prefix = $(PREFIX)
 BINDIR = $(prefix)/bin#			where to install executables
 MANDIR = $(prefix)/man/man$(manext)#	where to install man pages
 INSTALLEDBIN = $(BINDIR)/funzip$E $(BINDIR)/unzip$E $(BINDIR)/unzipsfx$E \
@@ -797,6 +797,11 @@
 	 AF="-DNO_UNDERLINE -Djecxz=jcxz -DALIGNMENT='.align 16' $(AF)"
 	$(STRIP) $(UNZIPS)
 
+# IRIX 6.5.x
+irix_gcc:	unix_make
+	$(MAKE) unzips CC=gcc LD=gcc CFLAGS="-O2 -DSYSV -DNO_LCHOWN -DNO_LCHMOD" LF2=""
+	$(STRIP) $(UNZIPS)
+
 # "ISI machine (68025 CPU)" (based on e-mail from Rob White <rsw@tfs.com>;
 # no further information).  May also need DIRENT defined.
 isi:		unix_make