diff --git a/unix/vncviewer/Makefile.am b/unix/vncviewer/Makefile.am
index 2b1e966..cfbe430 100644
--- a/unix/vncviewer/Makefile.am
+++ b/unix/vncviewer/Makefile.am
@@ -18,4 +18,8 @@
 	$(top_builddir)/common/rdr/librdr.la \
 	@X_PRE_LIBS@ @X_LIBS@ -lXext -lX11 @X_EXTRA_LIBS@ @GNUTLS_LIBS@ # @LIBINTL@
 
+if INCLUDED_ZLIB
+vncviewer_LDADD += $(top_builddir)/common/zlib/libz.la
+endif
+
 EXTRA_DIST = vncviewer.man