diff --git a/vpn_slice/__main__.py b/vpn_slice/__main__.py
index 13d0433..4959e3b 100755
--- a/vpn_slice/__main__.py
+++ b/vpn_slice/__main__.py
@@ -202,18 +202,22 @@ def do_post_connect(env, args):
     if args.verbose:
         print("Looking up %d hosts using VPN DNS servers..." % len(args.hosts), file=stderr)
     for host in args.hosts:
-        ips = providers.dns.lookup_host(
-                host, dns_servers=env.dns, search_domains=args.domain,
-                bind_addresses=env.myaddrs)
-        if ips is None:
-            print("WARNING: Lookup for %s on VPN DNS servers failed." % host, file=stderr)
+        try:
+           ips = providers.dns.lookup_host(
+                   host, dns_servers=env.dns, search_domains=args.domain,
+                   bind_addresses=env.myaddrs)
+        except Exception as e:
+            print("WARNING: Lookup for %s on VPN DNS servers failed:\n\t%s" % (host, e), file=stderr)
         else:
-            if args.verbose:
-                print("  %s = %s" % (host, ', '.join(map(str, ips))), file=stderr)
-            ip_routes.update(ips)
-            if args.host_names:
-                names = names_for(host, args.domain, args.short_names)
-                host_map.extend((ip, names) for ip in ips)
+            if ips is None:
+                print("WARNING: Lookup for %s on VPN DNS servers returned nothing." % host, file=stderr)
+            else:
+                if args.verbose:
+                    print("  %s = %s" % (host, ', '.join(map(str, ips))), file=stderr)
+                ip_routes.update(ips)
+                if args.host_names:
+                    names = names_for(host, args.domain, args.short_names)
+                    host_map.extend((ip, names) for ip in ips)
     for ip, aliases in args.aliases.items():
         host_map.append((ip, aliases))
 
diff --git a/vpn_slice/posix.py b/vpn_slice/posix.py
index dfd9202..0ca7108 100644
--- a/vpn_slice/posix.py
+++ b/vpn_slice/posix.py
@@ -47,10 +47,10 @@ def lookup_host(self, hostname, dns_servers, *, bind_addresses=None, search_doma
         # actually fetch results
         result = set()
         for cl in all_cls:
-            p = subprocess.Popen(cl, stdout=subprocess.PIPE, universal_newlines=True)
-            output, _ = p.communicate()
+            p = subprocess.Popen(cl, stdout=subprocess.PIPE, stderr=subprocess.PIPE, universal_newlines=True)
+            output, stderr = p.communicate()
             if p.returncode != 0:
-                return None
+                raise subprocess.CalledProcessError(p.returncode, cmd, output=output, stderr=stderr)
             for line in output.splitlines():
                 try:
                     result.add(ip_address(line.strip()))