diff --git a/cpplint/cpplint.py b/cpplint/cpplint.py
index 0445454f6..159dbbb07 100755
--- a/cpplint/cpplint.py
+++ b/cpplint/cpplint.py
@@ -136,6 +136,22 @@
       the top-level categories like 'build' and 'whitespace' will
       also be printed. If 'detailed' is provided, then a count
       is provided for each category like 'build/class'.
+
+    root=subdir
+      The root directory used for deriving header guard CPP variable.
+      By default, the header guard CPP variable is calculated as the relative
+      path to the directory that contains .git, .hg, or .svn.  When this flag
+      is specified, the relative path is calculated from the specified
+      directory. If the specified directory does not exist, this flag is
+      ignored.
+
+      Examples:
+        Assuing that src/.git exists, the header guard CPP variables for
+        src/chrome/browser/ui/browser.h are:
+
+        No flag => CHROME_BROWSER_UI_BROWSER_H_
+        --root=chrome => BROWSER_UI_BROWSER_H_
+        --root=chrome/browser => UI_BROWSER_H_
 """
 
 # We categorize each error message we print.  Here are the categories.
@@ -336,6 +352,10 @@
 # on which those errors are expected and should be suppressed.
 _error_suppressions = {}
 
+# The root directory used for deriving header guard CPP variable.
+# This is set by --root flag.
+_root = None
+
 def ParseNolintSuppressions(filename, raw_line, linenum, error):
   """Updates the global list of error-suppressions.
 
@@ -1102,7 +1122,10 @@ def GetHeaderGuardCPPVariable(filename):
   filename = re.sub(r'/\.flymake/([^/]*)$', r'/\1', filename)
 
   fileinfo = FileInfo(filename)
-  return re.sub(r'[-./\s]', '_', fileinfo.RepositoryName()).upper() + '_'
+  file_path_from_root = fileinfo.RepositoryName()
+  if _root:
+    file_path_from_root = re.sub('^' + _root + os.sep, '', file_path_from_root)
+  return re.sub(r'[-./\s]', '_', file_path_from_root).upper() + '_'
 
 
 def CheckForHeaderGuard(filename, lines, error):
@@ -3933,7 +3956,8 @@ def ParseArguments(args):
   try:
     (opts, filenames) = getopt.getopt(args, '', ['help', 'output=', 'verbose=',
                                                  'counting=',
-                                                 'filter='])
+                                                 'filter=',
+                                                 'root='])
   except getopt.GetoptError:
     PrintUsage('Invalid arguments.')
 
@@ -3959,6 +3983,9 @@ def ParseArguments(args):
       if val not in ('total', 'toplevel', 'detailed'):
         PrintUsage('Valid counting options are total, toplevel, and detailed')
       counting_style = val
+    elif opt == '--root':
+      global _root
+      _root = val
 
   if not filenames:
     PrintUsage('No files were specified.')
diff --git a/cpplint/cpplint_test_header.h b/cpplint/cpplint_test_header.h
new file mode 100644
index 000000000..4307e8008
--- /dev/null
+++ b/cpplint/cpplint_test_header.h
@@ -0,0 +1 @@
+// A test header for cpplint_unittest.py.
diff --git a/cpplint/cpplint_unittest.py b/cpplint/cpplint_unittest.py
index 907e36415..a195e9132 100755
--- a/cpplint/cpplint_unittest.py
+++ b/cpplint/cpplint_unittest.py
@@ -2588,6 +2588,29 @@ def testBuildHeaderGuard(self):
               '  [build/header_guard] [5]' % expected_guard),
           error_collector.ResultList())
 
+  def testBuildHeaderGuardWithRoot(self):
+    file_path = os.path.join(os.path.dirname(os.path.abspath(__file__)),
+                             'cpplint_test_header.h')
+    file_info = cpplint.FileInfo(file_path)
+    if file_info.FullName() == file_info.RepositoryName():
+      # When FileInfo cannot deduce the root directory of the repository,
+      # FileInfo.RepositoryName returns the same value as FileInfo.FullName.
+      # This can happen when this source file was obtained without .svn or
+      # .git directory. (e.g. using 'svn export' or 'git archive').
+      # Skip this test in such a case because --root flag makes sense only
+      # when the root directory of the repository is properly deduced.
+      return
+
+    self.assertEquals('CPPLINT_CPPLINT_TEST_HEADER_H_',
+                      cpplint.GetHeaderGuardCPPVariable(file_path))
+    cpplint._root = 'cpplint'
+    self.assertEquals('CPPLINT_TEST_HEADER_H_',
+                      cpplint.GetHeaderGuardCPPVariable(file_path))
+    # --root flag is ignored if an non-existent directory is specified.
+    cpplint._root = 'NON_EXISTENT_DIR'
+    self.assertEquals('CPPLINT_CPPLINT_TEST_HEADER_H_',
+                      cpplint.GetHeaderGuardCPPVariable(file_path))
+
   def testBuildInclude(self):
     # Test that include statements have slashes in them.
     self.TestLint('#include "foo.h"',