diff --git a/tools/gyp/pylib/gyp/xcode_emulation.py b/tools/gyp/pylib/gyp/xcode_emulation.py
index 72bb53a40d..f1a839a2f5 100644
--- a/tools/gyp/pylib/gyp/xcode_emulation.py
+++ b/tools/gyp/pylib/gyp/xcode_emulation.py
@@ -1471,6 +1471,8 @@ def _GetXcodeEnv(xcode_settings, built_products_dir, srcroot, configuration,
     sdk_root = xcode_settings._SdkRoot(configuration)
     if not sdk_root:
       sdk_root = xcode_settings._XcodeSdkPath('')
+    if sdk_root is None:
+      sdk_root = ''
     env['SDKROOT'] = sdk_root
 
   if not additional_settings: