diff --git a/django/test/utils.py b/django/test/utils.py
index 057969503d..419180eed3 100644
--- a/django/test/utils.py
+++ b/django/test/utils.py
@@ -598,10 +598,6 @@ def compare_xml(want, got):
     return check_element(want_root, got_root)
 
 
-def str_prefix(s):
-    return s % {'_': ''}
-
-
 class CaptureQueriesContext:
     """
     Context manager that captures queries executed by the specified connection.
@@ -659,29 +655,6 @@ class ignore_warnings(TestContextDecorator):
         self.catch_warnings.__exit__(*sys.exc_info())
 
 
-@contextmanager
-def patch_logger(logger_name, log_level, log_kwargs=False):
-    """
-    Context manager that takes a named logger and the logging level
-    and provides a simple mock-like list of messages received.
-
-    Use unittest.assertLogs() if you only need Python 3 support. This
-    private API will be removed after Python 2 EOL in 2020 (#27753).
-    """
-    calls = []
-
-    def replacement(msg, *args, **kwargs):
-        call = msg % args
-        calls.append((call, kwargs) if log_kwargs else call)
-    logger = logging.getLogger(logger_name)
-    orig = getattr(logger, log_level)
-    setattr(logger, log_level, replacement)
-    try:
-        yield calls
-    finally:
-        setattr(logger, log_level, orig)
-
-
 # On OSes that don't provide tzset (Windows), we can't set the timezone
 # in which the program runs. As a consequence, we must skip tests that
 # don't enforce a specific timezone (with timezone.override or equivalent),
diff --git a/docs/releases/3.0.txt b/docs/releases/3.0.txt
index 4dda131dbc..1c0a7d1f23 100644
--- a/docs/releases/3.0.txt
+++ b/docs/releases/3.0.txt
@@ -235,6 +235,22 @@ Dropped support for PostgreSQL 9.4
 Upstream support for PostgreSQL 9.4 ends in December 2019. Django 3.0 supports
 PostgreSQL 9.5 and higher.
 
+Removed private Python 2 compatibility APIs
+-------------------------------------------
+
+While Python 2 support was removed in Django 2.0, some private APIs weren't
+removed from Django so that third party apps could continue using them until
+the Python 2 end-of-life.
+
+Since we expect apps to drop Python 2 compatibility when adding support for
+Django 3.0, we're removing these APIs at this time.
+
+* ``django.test.utils.str_prefix()`` - Strings don't have 'u' prefixes in
+  Python 3.
+
+* ``django.test.utils.patch_logger()`` - Use
+  :meth:`unittest.TestCase.assertLogs` instead.
+
 Miscellaneous
 -------------