diff --git a/plugins/Alias.py b/plugins/Alias.py
index 2845dd9a4..1312cb5ae 100644
--- a/plugins/Alias.py
+++ b/plugins/Alias.py
@@ -185,7 +185,10 @@ class Alias(callbacks.Privmsg):
             irc.error(msg, 'There is no such alias.')
     unfreeze = privmsgs.checkCapability(unfreeze, 'admin')
 
+    _invalidCharsRe = re.compile(r'[\[\]\s]')
     def addAlias(self, irc, name, alias, freeze=False):
+        if self._invalidCharsRe.search(name):
+            raise AliasError, 'Names cannot contain spaces or square brackets.'
         realName = callbacks.canonicalName(name)
         if name != realName:
             raise AliasError,'That name isn\'t valid.  Try %r instead'%realName
diff --git a/test/test_Alias.py b/test/test_Alias.py
index c02af884f..ea0ba2c2d 100644
--- a/test/test_Alias.py
+++ b/test/test_Alias.py
@@ -96,6 +96,8 @@ class AliasTestCase(PluginTestCase, PluginDocumentation):
 
     def testNonCanonicalName(self):
         self.assertError('alias FOO foo')
+        self.assertError('alias [] foo')
+        self.assertError('alias "foo bar" foo')
 
     def testNotCannotNestRaised(self):
         self.assertNotError('alias mytell "tell $channel $1"')