--- SAOImageDS9/funtools/util/Makefile.in.orig	2021-08-24 15:13:28.042362853 +0200
+++ SAOImageDS9/funtools/util/Makefile.in	2021-08-24 15:14:01.733015729 +0200
@@ -62,7 +62,7 @@
 #       zutil.o inflate.o infblock.o inftrees.o infcodes.o infutil.o inffast.o
 
 # the full set of libraries for linking
-LIBS	= -lm
+LIBS	= -lm -lz
 
 # To change the compiler switches, for example to change from -O
 # to -g, change the following line:
@@ -181,7 +181,7 @@
 gcat.o:		gcat.c gio.h
 
 gcat:		gcat.o $(LIB)
-		$(CC) $(LDFLAGS) gcat.o -o gcat $(LIB) $(LIBS) $(EXTRA_LIBS)
+		$(CC) $(LDFLAGS) gcat.o -o gcat $(LIB) $(LIBS)
 
 tparse.o:	tparse.c