--- a/python/mozbuild/mozbuild/frontend/gyp_reader.py
+++ b/python/mozbuild/mozbuild/frontend/gyp_reader.py
@@ -102,17 +102,17 @@ def read_from_gyp(config, path, output, 
     includes.extend(encode(mozpath.join(chrome_src, name))
         for name, _ in finder.find('*/supplement.gypi'))
 
     # Read the given gyp file and its dependencies.
     generator, flat_list, targets, data = \
         gyp.Load([path], format=b'mozbuild',
             default_variables=str_vars,
             includes=includes,
-            depth=encode(mozpath.dirname(path)),
+            depth=encode(chrome_src),
             params=params)
 
     # Process all targets from the given gyp files and its dependencies.
     # The path given to AllTargets needs to use os.sep, while the frontend code
     # gives us paths normalized with forward slash separator.
     for target in gyp.common.AllTargets(flat_list, targets, path.replace(b'/', os.sep)):
         build_file, target_name, toolset = gyp.common.ParseQualifiedTarget(target)