diff --git a/coremods/corecommands.py b/coremods/corecommands.py
index 9b5bb5c..0c30d9f 100644
--- a/coremods/corecommands.py
+++ b/coremods/corecommands.py
@@ -15,6 +15,15 @@ from pylinkirc.log import log
 
 def _login(irc, source, username):
     """Internal function to process logins."""
+
+    logindata = conf.conf['login'].get('accounts', {}).get(username, {})
+    network_filter = logindata.get('networks')
+
+    if network_filter and irc.name not in network_filter:
+        irc.error("You are not authorized to log in to %r on this network." % username)
+        log.warning("(%s) Failed login to %r from %s (wrong network: networks filter says %r but we got %r)", irc.name, username, irc.get_hostmask(source), ', '.join(network_filter), irc.name)
+        return
+
     irc.users[source].account = username
     irc.reply('Successfully logged in as %s.' % username)
     log.info("(%s) Successful login to %r by %s",
diff --git a/example-conf.yml b/example-conf.yml
index 37dbb12..9f27718 100644
--- a/example-conf.yml
+++ b/example-conf.yml
@@ -92,6 +92,9 @@ login:
             # (plain text) for backwards compatibility.
             encrypted: true
 
+            # Optional: allows limiting this login to users from certain networks only (case sensitive).
+            #networks: ["network1", "network2"]
+
 permissions:
     # Permissions are described in more detail in example-permissions.yml, if you want to
     # customize permissions further.