diff --git a/SConstruct b/SConstruct
index d791033e7..ae0fc4b6c 100755
--- a/SConstruct
+++ b/SConstruct
@@ -112,6 +112,7 @@ For more details, see:
 import itertools
 import os
 import re
+import shutil
 import subprocess
 import sys
 
@@ -266,15 +267,21 @@ against the gem5 style rules on hg commit and qrefresh commands.  This
 script will now install the hook in your .hg/hgrc file.
 Press enter to continue, or ctrl-c to abort: """
 
+mercurial_style_upgrade_message = """
+Your Mercurial style hooks are not up-to-date. This script will now
+try to automatically update them. A backup of your hgrc will be saved
+in .hg/hgrc.old.
+Press enter to continue, or ctrl-c to abort: """
+
 mercurial_style_hook = """
 # The following lines were automatically added by gem5/SConstruct
 # to provide the gem5 style-checking hooks
 [extensions]
-style = %s/util/style.py
+hgstyle = %s/util/hgstyle.py
 
 [hooks]
-pretxncommit.style = python:style.check_style
-pre-qrefresh.style = python:style.check_style
+pretxncommit.style = python:hgstyle.check_style
+pre-qrefresh.style = python:hgstyle.check_style
 # End of SConstruct additions
 
 """ % (main.root.abspath)
@@ -290,16 +297,52 @@ hook. It is important.
 # install a hook in, or there's no interactive terminal to prompt.
 if not GetOption('ignore_style') and hgdir.exists() and sys.stdin.isatty():
     style_hook = True
+    style_hooks = tuple()
+    hgrc = hgdir.File('hgrc')
+    hgrc_old = hgdir.File('hgrc.old')
     try:
         from mercurial import ui
         ui = ui.ui()
-        ui.readconfig(hgdir.File('hgrc').abspath)
-        style_hook = ui.config('hooks', 'pretxncommit.style', None) and \
-                     ui.config('hooks', 'pre-qrefresh.style', None)
+        ui.readconfig(hgrc.abspath)
+        style_hooks = (ui.config('hooks', 'pretxncommit.style', None),
+                       ui.config('hooks', 'pre-qrefresh.style', None))
+        style_hook = all(style_hooks)
+        style_extension = ui.config('extensions', 'style', None)
     except ImportError:
         print mercurial_lib_not_found
 
-    if not style_hook:
+    if "python:style.check_style" in style_hooks:
+        # Try to upgrade the style hooks
+        print mercurial_style_upgrade_message
+        # continue unless user does ctrl-c/ctrl-d etc.
+        try:
+            raw_input()
+        except:
+            print "Input exception, exiting scons.\n"
+            sys.exit(1)
+        shutil.copyfile(hgrc.abspath, hgrc_old.abspath)
+        re_style_hook = re.compile(r"^([^=#]+)\.style\s*=\s*([^#\s]+).*")
+        re_style_extension = re.compile("style\s*=\s*([^#\s]+).*")
+        with open(hgrc_old.abspath, 'r') as old, \
+             open(hgrc.abspath, 'w') as new:
+
+            for l in old:
+                m_hook = re_style_hook.match(l)
+                m_ext = re_style_extension.match(l)
+                if m_hook:
+                    hook, check = m_hook.groups()
+                    if check != "python:style.check_style":
+                        print "Warning: %s.style is using a non-default " \
+                            "checker: %s" % (hook, check)
+                    if hook not in ("pretxncommit", "pre-qrefresh"):
+                        print "Warning: Updating unknown style hook: %s" % hook
+
+                    l = "%s.style = python:hgstyle.check_style\n" % hook
+                elif m_ext and m_ext.group(1) == style_extension:
+                    l = "hgstyle = %s/util/hgstyle.py\n" % main.root.abspath
+
+                new.write(l)
+    elif not style_hook:
         print mercurial_style_message,
         # continue unless user does ctrl-c/ctrl-d etc.
         try:
@@ -310,9 +353,8 @@ if not GetOption('ignore_style') and hgdir.exists() and sys.stdin.isatty():
         hgrc_path = '%s/.hg/hgrc' % main.root.abspath
         print "Adding style hook to", hgrc_path, "\n"
         try:
-            hgrc = open(hgrc_path, 'a')
-            hgrc.write(mercurial_style_hook)
-            hgrc.close()
+            with open(hgrc_path, 'a') as f:
+                f.write(mercurial_style_hook)
         except:
             print "Error updating", hgrc_path
             sys.exit(1)
diff --git a/util/style.py b/util/hgstyle.py
similarity index 100%
rename from util/style.py
rename to util/hgstyle.py