--- pngnq-1.0.old/src/Makefile.in
+++ pngnq-1.0/src/Makefile.in
@@ -97,7 +97,7 @@
 INSTALL_STRIP_PROGRAM = @INSTALL_STRIP_PROGRAM@
 LDFLAGS = @LDFLAGS@
 LIBOBJS = @LIBOBJS@
-LIBS = @LIBS@
+LIBS = @LIBS@ -lz
 LTLIBOBJS = @LTLIBOBJS@
 MAKEINFO = @MAKEINFO@
 OBJEXT = @OBJEXT@