diff --git a/setup.cfg b/setup.cfg
index a0b89d02e50..9ba33169ae7 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -3,7 +3,7 @@ doc_files = docs extras AUTHORS INSTALL LICENSE README.rst
 install-script = scripts/rpm-install.sh
 
 [flake8]
-exclude = build,.git,./django/utils/lru_cache.py,./django/utils/six.py,./django/conf/app_template/*,./django/dispatch/weakref_backports.py,./tests/.env,./xmlrunner,tests/view_tests/tests/py3_test_debug.py
+exclude = build,.git,./django/utils/lru_cache.py,./django/utils/six.py,./django/conf/app_template/*,./django/dispatch/weakref_backports.py,./tests/.env,./xmlrunner,tests/view_tests/tests/py3_test_debug.py,tests/template_tests/annotated_tag_function.py
 ignore = E123,E128,E402,W503,E731,W601
 max-line-length = 119
 
diff --git a/tests/template_tests/annotated_tag_function.py b/tests/template_tests/annotated_tag_function.py
new file mode 100644
index 00000000000..bd3017c27c7
--- /dev/null
+++ b/tests/template_tests/annotated_tag_function.py
@@ -0,0 +1,8 @@
+from django import template
+
+register = template.Library()
+
+
+@register.simple_tag()
+def annotated_tag_function(val: int):
+    return val
diff --git a/tests/template_tests/test_custom.py b/tests/template_tests/test_custom.py
index 1b639538606..48252e17885 100644
--- a/tests/template_tests/test_custom.py
+++ b/tests/template_tests/test_custom.py
@@ -1,6 +1,7 @@
 from __future__ import unicode_literals
 
 import os
+from unittest import skipUnless
 
 from django.template import Context, Engine, TemplateSyntaxError
 from django.template.base import Node
@@ -380,3 +381,9 @@ class TemplateTagLoadingTests(SimpleTestCase):
                 'working_egg': 'tagsegg.templatetags.working_egg',
             })
             engine.from_string(ttext)
+
+    @skipUnless(six.PY3, "Python 3 only -- Python 2 doesn't have annotations.")
+    def test_load_annotated_function(self):
+        Engine(libraries={
+            'annotated_tag_function': 'template_tests.annotated_tag_function',
+        })