diff --git a/lib/spack/spack/main.py b/lib/spack/spack/main.py
index 1eeec8827bb..31a4bfe4ed5 100644
--- a/lib/spack/spack/main.py
+++ b/lib/spack/spack/main.py
@@ -12,6 +12,7 @@
 
 import argparse
 import inspect
+import operator
 import os
 import os.path
 import pstats
@@ -188,6 +189,10 @@ def _format_actions_usage(self, actions, groups):
             usage = '[-%s] %s' % (chars, usage)
         return usage.strip()
 
+    def add_arguments(self, actions):
+        actions = sorted(actions, key=operator.attrgetter('option_strings'))
+        super(SpackHelpFormatter, self).add_arguments(actions)
+
 
 class SpackArgumentParser(argparse.ArgumentParser):
     def format_help_sections(self, level):