diff --git a/src/modules/Gz/configure.in b/src/modules/Gz/configure.in
index 4576722861dd7696625c27fd835ae06a51a20b63..076a38dcb2ddd36d0f303d7e7089082b4a448007 100644
--- a/src/modules/Gz/configure.in
+++ b/src/modules/Gz/configure.in
@@ -7,7 +7,7 @@ sinclude(../module_configure.in)
 if test x$with_zlib = xyes ; then
   AC_CHECK_HEADERS(zlib.h)
   if test $ac_cv_header_zlib_h = yes ; then
-    AC_CHECK_LIB(z, compress, [[LIBS="${LIBS-} -lz"]],
+    AC_CHECK_LIB(z, compress, [[AC_DEFINE(HAVE_LIBZ) ; LIBS="${LIBS-} -lz"]] ,
       AC_CHECK_LIB(gz, compress))
   fi
 fi