diff --git a/build/gyp/tools/mac_find_sdk.py b/build/gyp/tools/mac_find_sdk.py
new file mode 100644
index 0000000..230c2fd
--- /dev/null
+++ b/build/gyp/tools/mac_find_sdk.py
@@ -0,0 +1,93 @@
+#!/usr/bin/env python
+# Copyright 2016 PDFium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Prints the lowest locally available SDK version greater than or equal to a
+given minimum sdk version to standard output.
+
+Usage:
+  python mac_find_sdk.py 10.6  # Ignores SDKs < 10.6
+"""
+
+import os
+import re
+import subprocess
+import sys
+
+
+from optparse import OptionParser
+
+
+def parse_version(version_str):
+  """'10.6' => [10, 6]"""
+  return map(int, re.findall(r'(\d+)', version_str))
+
+
+def main():
+  parser = OptionParser()
+  parser.add_option("--verify",
+                    action="store_true", dest="verify", default=False,
+                    help="return the sdk argument and warn if it doesn't exist")
+  parser.add_option("--sdk_path",
+                    action="store", type="string", dest="sdk_path", default="",
+                    help="user-specified SDK path; bypasses verification")
+  parser.add_option("--print_sdk_path",
+                    action="store_true", dest="print_sdk_path", default=False,
+                    help="Additionaly print the path the SDK (appears first).")
+  options, args = parser.parse_args()
+  if len(args) != 1:
+    parser.error('Please specify a minimum SDK version')
+  min_sdk_version = args[0]
+
+  job = subprocess.Popen(['xcode-select', '-print-path'],
+                         stdout=subprocess.PIPE,
+                         stderr=subprocess.STDOUT)
+  out, err = job.communicate()
+  if job.returncode != 0:
+    print >> sys.stderr, out
+    print >> sys.stderr, err
+    raise Exception(('Error %d running xcode-select, you might have to run '
+      '|sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer| '
+      'if you are using Xcode 4.') % job.returncode)
+  # The Developer folder moved in Xcode 4.3.
+  xcode43_sdk_path = os.path.join(
+      out.rstrip(), 'Platforms/MacOSX.platform/Developer/SDKs')
+  if os.path.isdir(xcode43_sdk_path):
+    sdk_dir = xcode43_sdk_path
+  else:
+    sdk_dir = os.path.join(out.rstrip(), 'SDKs')
+  sdks = [re.findall('^MacOSX(10\.\d+)\.sdk$', s) for s in os.listdir(sdk_dir)]
+  sdks = [s[0] for s in sdks if s]  # [['10.5'], ['10.6']] => ['10.5', '10.6']
+  sdks = [s for s in sdks  # ['10.5', '10.6'] => ['10.6']
+          if parse_version(s) >= parse_version(min_sdk_version)]
+  if not sdks:
+    raise Exception('No %s+ SDK found' % min_sdk_version)
+  best_sdk = sorted(sdks, key=parse_version)[0]
+
+  if options.verify and best_sdk != min_sdk_version and not options.sdk_path:
+    print >> sys.stderr, ''
+    print >> sys.stderr, '                                           vvvvvvv'
+    print >> sys.stderr, ''
+    print >> sys.stderr, \
+        'This build requires the %s SDK, but it was not found on your system.' \
+        % min_sdk_version
+    print >> sys.stderr, \
+        'Either install it, or explicitly set mac_sdk in your GYP_DEFINES.'
+    print >> sys.stderr, ''
+    print >> sys.stderr, '                                           ^^^^^^^'
+    print >> sys.stderr, ''
+    return min_sdk_version
+
+  if options.print_sdk_path:
+    print subprocess.check_output(['xcodebuild', '-version', '-sdk',
+                                   'macosx' + best_sdk, 'Path']).strip()
+
+  return best_sdk
+
+
+if __name__ == '__main__':
+  if sys.platform != 'darwin':
+    raise Exception("This script only runs on Mac")
+  print main()
+  sys.exit(0)
diff --git a/build/standalone.gypi b/build/standalone.gypi
index f0ab3a9..dfd5617 100644
--- a/build/standalone.gypi
+++ b/build/standalone.gypi
@@ -416,6 +416,15 @@
             'xcode_settings': {'OTHER_LDFLAGS': ['-Wl,-search_paths_first']},
           }],
         ],  # target_conditions
+        'variables': {
+          'mac_sdk_min': '10.10',
+          'mac_sdk%': '<!(python <(DEPTH)/build/gyp/tools/mac_find_sdk.py <(mac_sdk_min))',
+        },
+        'xcode_settings': {
+          'SDKROOT': 'macosx<(mac_sdk)',  # -isysroot
+          # See comment in Chromium's common.gypi for why this is needed.
+          'SYMROOT': '<(DEPTH)/xcodebuild',
+        },
       }],  # OS=="mac"
       ['v8_use_external_startup_data==1', {
         'defines': [
@@ -432,11 +441,6 @@
       }],
     ],
   },
-  'xcode_settings': {
-    'SDKROOT': 'macosx10.10',  # -isysroot
-    # See comment in Chromium's common.gypi for why this is needed.
-    'SYMROOT': '<(DEPTH)/xcodebuild',
-  },
   'conditions': [
     ['OS=="linux" or OS=="mac"', {
       'conditions': [