diff --git a/sphinx/__init__.py b/sphinx/__init__.py
index 69b379cd3..7a5684c85 100644
--- a/sphinx/__init__.py
+++ b/sphinx/__init__.py
@@ -74,42 +74,7 @@ def main(argv=sys.argv[1:]):
 def build_main(argv=sys.argv[1:]):
     # type: (List[str]) -> int
     """Sphinx build "main" command-line entry."""
-    if (sys.version_info[:3] < (2, 7, 0) or
-       (3, 0, 0) <= sys.version_info[:3] < (3, 4, 0)):
-        sys.stderr.write('Error: Sphinx requires at least Python 2.7 or 3.4 to run.\n')
-        return 1
-    try:
-        from sphinx import cmdline
-    except ImportError:
-        err = sys.exc_info()[1]
-        errstr = str(err)
-        if errstr.lower().startswith('no module named'):
-            whichmod = errstr[16:]
-            hint = ''
-            if whichmod.startswith('docutils'):
-                whichmod = 'Docutils library'
-            elif whichmod.startswith('jinja'):
-                whichmod = 'Jinja2 library'
-            elif whichmod == 'roman':
-                whichmod = 'roman module (which is distributed with Docutils)'
-                hint = ('This can happen if you upgraded docutils using\n'
-                        'easy_install without uninstalling the old version'
-                        'first.\n')
-            else:
-                whichmod += ' module'
-            sys.stderr.write('Error: The %s cannot be found. '
-                             'Did you install Sphinx and its dependencies '
-                             'correctly?\n' % whichmod)
-            if hint:
-                sys.stderr.write(hint)
-            return 1
-        raise
-
-    import sphinx.util.docutils
-    if sphinx.util.docutils.__version_info__ < (0, 10):
-        sys.stderr.write('Error: Sphinx requires at least Docutils 0.10 to '
-                         'run.\n')
-        return 1
+    from sphinx import cmdline
     return cmdline.main(argv)  # type: ignore