diff --git a/beets/ui/__init__.py b/beets/ui/__init__.py
index 4ab49d516..da78fbb3f 100644
--- a/beets/ui/__init__.py
+++ b/beets/ui/__init__.py
@@ -775,9 +775,9 @@ class SubcommandsOptionParser(optparse.OptionParser):
         return self.parse_args(args)
 
     def parse_subcommand(self, args):
-        """Given the `args` left unused by a typical OptionParser
-        `parse_args`, return the invoked subcommand, the subcommand
-        options, and the subcommand arguments.
+        """Given the `args` left unused by a `parse_global_options`,
+        return the invoked subcommand, the subcommand options, and the
+        subcommand arguments.
         """
         # Help is default command
         if not args:
diff --git a/beets/ui/commands.py b/beets/ui/commands.py
index 69d373d82..14f2bf0a4 100644
--- a/beets/ui/commands.py
+++ b/beets/ui/commands.py
@@ -23,6 +23,7 @@ import time
 import itertools
 import codecs
 import platform
+import re
 
 import beets
 from beets import ui
@@ -111,6 +112,7 @@ fields_cmd = ui.Subcommand(
 fields_cmd.func = fields_func
 default_commands.append(fields_cmd)
 
+
 # help: Print help text for commands
 
 class HelpCommand(ui.Subcommand):
@@ -1521,7 +1523,8 @@ def completion_script(commands):
         command_names.append(name)
 
         for alias in cmd.aliases:
-            aliases[alias] = name
+            if re.match(r'^\w+$', alias):
+                aliases[alias] = name
 
         options[name] = {'flags': [], 'opts': []}
         for opts in cmd.parser._get_all_options()[1:]:
@@ -1540,9 +1543,6 @@ def completion_script(commands):
         'opts': '-l --library -c --config -d --directory -h --help'.split(' ')
     }
 
-    # Help subcommand
-    command_names.append('help')
-
     # Add flags common to all commands
     options['_common'] = {
         'flags': ['-h', '--help']