diff --git a/CHANGES b/CHANGES
index 282c6106f..4a94fc3e6 100644
--- a/CHANGES
+++ b/CHANGES
@@ -47,6 +47,7 @@ Deprecated
   argument has been deprecated
 * ``Config.check_types()`` is deprecated
 * ``Config.check_unicode()`` is deprecated
+* ``sphinx.application.CONFIG_FILENAME`` is deprecated
 
 For more details, see `deprecation APIs list
 <http://www.sphinx-doc.org/en/master/extdev/index.html#deprecated-apis>`_
@@ -75,7 +76,7 @@ Features added
 * #4834: Ensure set object descriptions are reproducible.
 * #4828: Allow to override :confval:`numfig_format` partially.  Full definition
   is not needed.
-* Add ``Config.from_conf_py()`` classmethod to create a new config object from
+* Add ``Config.read()`` classmethod to create a new config object from
   configuration file
 
 Bugs fixed
diff --git a/doc/extdev/index.rst b/doc/extdev/index.rst
index f0236ed3c..e096bf993 100644
--- a/doc/extdev/index.rst
+++ b/doc/extdev/index.rst
@@ -119,6 +119,11 @@ The following is a list of deprecated interface.
      - 4.0
      - :meth:`~sphinx.application.Sphinx.add_css_file()`
 
+   * - ``sphinx.application.CONFIG_FILENAME``
+     - 1.8
+     - 3.0
+     - ``sphinx.config.CONFIG_FILENAME``
+
    * - ``Config.check_unicode()``
      - 1.8
      - 3.0
@@ -133,7 +138,7 @@ The following is a list of deprecated interface.
        ``Config.__init__()``
      - 1.8
      - 3.0
-     - ``Config.from_conf_py()``
+     - ``Config.read()``
 
    * - ``sphinx.versioning.prepare()``
      - 1.8
diff --git a/sphinx/application.py b/sphinx/application.py
index 26aec9e39..0fbc6d2cb 100644
--- a/sphinx/application.py
+++ b/sphinx/application.py
@@ -26,6 +26,7 @@ from six.moves import cStringIO
 
 import sphinx
 from sphinx import package_dir, locale
+from sphinx.config import CONFIG_FILENAME  # NOQA # for compatibility (RemovedInSphinx30)
 from sphinx.config import Config, check_unicode
 from sphinx.deprecation import (
     RemovedInSphinx20Warning, RemovedInSphinx30Warning, RemovedInSphinx40Warning
@@ -108,7 +109,6 @@ builtin_extensions = (
     'alabaster',
 )  # type: Tuple[unicode, ...]
 
-CONFIG_FILENAME = 'conf.py'
 ENV_PICKLE_FILENAME = 'environment.pickle'
 
 logger = logging.getLogger(__name__)
@@ -190,8 +190,7 @@ class Sphinx(object):
         if self.confdir is None:
             self.config = Config({}, confoverrides or {})
         else:
-            self.config = Config.from_conf_py(path.join(self.confdir, CONFIG_FILENAME),
-                                              confoverrides or {}, self.tags)
+            self.config = Config.read(self.confdir, confoverrides or {}, self.tags)
             check_unicode(self.config)
 
         # initialize some limited config variables before initialize i18n and loading
diff --git a/sphinx/config.py b/sphinx/config.py
index 0a7f71805..58e5be277 100644
--- a/sphinx/config.py
+++ b/sphinx/config.py
@@ -34,6 +34,7 @@ if False:
 
 logger = logging.getLogger(__name__)
 
+CONFIG_FILENAME = 'conf.py'
 copyright_year_re = re.compile(r'^((\d{4}-)?)(\d{4})(?=[ ,])')
 
 if PY3:
@@ -148,7 +149,7 @@ class Config(object):
         if len(args) == 4:
             # old style arguments: (dirname, filename, overrides, tags)
             warnings.warn('The argument of Config() class has been changed. '
-                          'Use Config.from_conf_py() to read configuration from conf.py.',
+                          'Use Config.read() to read configuration from conf.py.',
                           RemovedInSphinx30Warning)
             dirname, filename, overrides, tags = args
             if dirname is None:
@@ -177,9 +178,10 @@ class Config(object):
         self.extensions = config.get('extensions', [])  # type: List[unicode]
 
     @classmethod
-    def from_conf_py(cls, filename, overrides=None, tags=None):
+    def read(cls, confdir, overrides=None, tags=None):
         # type: (unicode, Dict, Tags) -> Config
         """Create a Config object from configuration file."""
+        filename = path.join(confdir, CONFIG_FILENAME)
         namespace = eval_config_file(filename, tags)
         return cls(namespace, overrides or {})
 
diff --git a/tests/test_config.py b/tests/test_config.py
index 078a05a2a..e3b79c835 100644
--- a/tests/test_config.py
+++ b/tests/test_config.py
@@ -124,14 +124,14 @@ def test_errors_warnings(logger, tempdir):
     # test the error for syntax errors in the config file
     (tempdir / 'conf.py').write_text(u'project = \n', encoding='ascii')
     with pytest.raises(ConfigError) as excinfo:
-        Config.from_conf_py(tempdir / 'conf.py', {}, None)
+        Config.read(tempdir, {}, None)
     assert 'conf.py' in str(excinfo.value)
 
     # test the automatic conversion of 2.x only code in configs
     (tempdir / 'conf.py').write_text(
         u'# -*- coding: utf-8\n\nproject = u"Jägermeister"\n',
         encoding='utf-8')
-    cfg = Config.from_conf_py(tempdir / 'conf.py', {}, None)
+    cfg = Config.read(tempdir, {}, None)
     cfg.init_values()
     assert cfg.project == u'Jägermeister'
     assert logger.called is False
@@ -143,7 +143,7 @@ def test_errors_warnings(logger, tempdir):
         return
     (tempdir / 'conf.py').write_text(
         u'# -*- coding: latin-1\nproject = "fooä"\n', encoding='latin-1')
-    cfg = Config.from_conf_py(tempdir / 'conf.py', {}, None)
+    cfg = Config.read(tempdir, {}, None)
 
     assert logger.warning.called is False
     cfg.check_unicode()
@@ -202,7 +202,7 @@ def test_config_eol(logger, tempdir):
     configfile = tempdir / 'conf.py'
     for eol in (b'\n', b'\r\n'):
         configfile.write_bytes(b'project = "spam"' + eol)
-        cfg = Config.from_conf_py(tempdir / 'conf.py', {}, None)
+        cfg = Config.read(tempdir, {}, None)
         cfg.init_values()
         assert cfg.project == u'spam'
         assert logger.called is False