diff --git a/mitmproxy/options.py b/mitmproxy/options.py
index 9fc6966bc..561461538 100644
--- a/mitmproxy/options.py
+++ b/mitmproxy/options.py
@@ -69,7 +69,7 @@ class Options(optmanager.OptManager):
         )
         self.add_option(
             "allow_hosts", Sequence[str], [],
-            "Opposite of --ignore_hosts."
+            "Opposite of --ignore-hosts."
         )
         self.add_option(
             "listen_host", str, "",
diff --git a/test/mitmproxy/proxy/test_config.py b/test/mitmproxy/proxy/test_config.py
index 1da031c66..1319d1a9d 100644
--- a/test/mitmproxy/proxy/test_config.py
+++ b/test/mitmproxy/proxy/test_config.py
@@ -17,3 +17,12 @@ class TestProxyConfig:
         opts.certs = [tdata.path("mitmproxy/data/dumpfile-011")]
         with pytest.raises(exceptions.OptionsError, match="Invalid certificate format"):
             ProxyConfig(opts)
+
+    def test_cannot_set_both_allow_and_filter_options(self):
+        opts = options.Options()
+        opts.ignore_hosts = ["foo"]
+        opts.allow_hosts = ["bar"]
+        with pytest.raises(exceptions.OptionsError, match="--ignore-hosts and --allow-hosts are "
+                                                          "mutually exclusive; please choose "
+                                                          "one."):
+            ProxyConfig(opts)