diff --git a/sphinx/util/__init__.py b/sphinx/util/__init__.py
index e6c59df09..6a28432e3 100644
--- a/sphinx/util/__init__.py
+++ b/sphinx/util/__init__.py
@@ -18,6 +18,7 @@ import sys
 import tempfile
 import traceback
 import unicodedata
+import warnings
 from codecs import BOM_UTF8
 from collections import deque
 from datetime import datetime
@@ -29,6 +30,7 @@ from six import text_type, binary_type, itervalues
 from six.moves import range
 from six.moves.urllib.parse import urlsplit, urlunsplit, quote_plus, parse_qsl, urlencode
 
+from sphinx.deprecation import RemovedInSphinx30Warning
 from sphinx.errors import PycodeError, SphinxParallelError, ExtensionError
 from sphinx.util import logging
 from sphinx.util.console import strip_colors, colorize, bold, term_width_line  # type: ignore
@@ -172,6 +174,9 @@ def copy_static_entry(source, targetdir, builder, context={},
 
     Handles all possible cases of files, directories and subdirectories.
     """
+    warnings.warn('sphinx.util.copy_static_entry is deprecated for removal',
+                  RemovedInSphinx30Warning)
+
     if exclude_matchers:
         relpath = relative_path(path.join(builder.srcdir, 'dummy'), source)
         for matcher in exclude_matchers:
diff --git a/sphinx/util/osutil.py b/sphinx/util/osutil.py
index b52fde0d6..21464bbe6 100644
--- a/sphinx/util/osutil.py
+++ b/sphinx/util/osutil.py
@@ -19,11 +19,14 @@ import re
 import shutil
 import sys
 import time
+import warnings
 from io import BytesIO, StringIO
 from os import path
 
 from six import PY2, PY3, text_type
 
+from sphinx.deprecation import RemovedInSphinx30Warning
+
 if False:
     # For type annotation
     from typing import Any, Iterator, List, Tuple, Union  # NOQA
@@ -181,8 +184,10 @@ def make_filename(string):
 
 def ustrftime(format, *args):
     # type: (unicode, Any) -> unicode
-    # [DEPRECATED] strftime for unicode strings
-    # It will be removed at Sphinx-1.5
+    """[DEPRECATED] strftime for unicode strings."""
+    warnings.warn('sphinx.util.osutil.ustrtime is deprecated for removal',
+                  RemovedInSphinx30Warning)
+
     if not args:
         # If time is not specified, try to use $SOURCE_DATE_EPOCH variable
         # See https://wiki.debian.org/ReproducibleBuilds/TimestampsProposal