@@ -135,6 +135,7 @@ REFPAGES_URL  = 'https://registry.khronos.org/OpenGL-Refpages/'

 REGISTRY_URL  = 'https://registry.khronos.org/OpenGL/'

 REFPAGES_GIT  = 'https://github.com/KhronosGroup/OpenGL-Refpages'

 XML_PATH      = 'xml/gl.xml'

+USER_AGENT    = 'Mozilla/5.0'

 REGEX         = r'\b(gl|GL_)[0-9A-Z][0-9A-Za-z_]+\b'

 EXCLUDE_DIRS  = ['.?*', '_*']

 EXCLUDE_FILES = ['README*', 'TODO*']

@@ -632,6 +633,9 @@ def refs_all(name):

 ## Main

 def main():

+    opener = urllib.request.build_opener()

+    opener.addheaders = [('User-Agent', USER_AGENT)]

+    urllib.request.install_opener(opener)

     args = docopt.docopt(__doc__)

     if args['xml']:           edit(xml          ())

     if args['xml-path']:      page(xml          ())