diff --git a/configure.ac.in b/configure.ac.in
index 4af1df18..d8ce8b68 100644
--- a/configure.ac.in
+++ b/configure.ac.in
@@ -223,21 +223,21 @@ AC_ARG_ENABLE([portmon],
                              [disable if you do not want tcp (ip4) port monitoring @<:@default=yes@:>@]),
               [want_portmon="$enableval"], [want_portmon=yes])
 
-AM_CONDITIONAL(BUILD_PORT_MONITORS, test x$want_portmon = xyes)
-if test x$want_portmon = xyes; then
-  if test "x$uname" != xLinux; then
+if test x"$want_portmon" = xyes; then
+  if test x"$uname" != xLinux; then
       AC_MSG_NOTICE([port monitors not supported on $uname... disabling])
       want_portmon=no
   else
         AC_CHECK_HEADERS([netdb.h netinet/in.h netinet/tcp.h sys/socket.h arpa/inet.h], [], 
            [PORT_MONITORS_MISSING=yes])
-        if test "x$PORT_MONITORS_MISSING" = xyes; then
+        if test x"$PORT_MONITORS_MISSING" = xyes; then
               AC_MSG_ERROR([missing a needed network header for port monitoring])
         fi
 	WANT_GLIB=yes
 	AC_DEFINE(TCP_PORT_MONITOR, 1, [Define if you want tcp port monitoring support])
   fi
 fi
+AM_CONDITIONAL(BUILD_PORT_MONITORS, test x"$want_portmon" = xyes)
 
 
 dnl