diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index a20289d865..98e63ccfac 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -4,6 +4,8 @@ Changelog
 2.5 (xx.xx.xxxx) - IN DEVELOPMENT
 ~~~~~~~~~~~~~~~~
 
+* Fix: Set `SERVER_PORT` to 443 in `Page.dummy_request()` for HTTPS sites (Sergey Fedoseev)
+
 
 2.4 (xx.xx.xxxx) - IN DEVELOPMENT
 ~~~~~~~~~~~~~~~~
diff --git a/docs/releases/2.5.rst b/docs/releases/2.5.rst
index 0e0e640231..3e12b8f043 100644
--- a/docs/releases/2.5.rst
+++ b/docs/releases/2.5.rst
@@ -18,6 +18,8 @@ Other features
 Bug fixes
 ~~~~~~~~~
 
+ * Set ``SERVER_PORT`` to 443 in ``Page.dummy_request()`` for HTTPS sites (Sergey Fedoseev)
+
 
 Upgrade considerations
 ======================
diff --git a/wagtail/core/models.py b/wagtail/core/models.py
index 088202dd10..ad42af0989 100644
--- a/wagtail/core/models.py
+++ b/wagtail/core/models.py
@@ -1215,7 +1215,7 @@ class Page(AbstractPage, index.Indexed, ClusterableModel, metaclass=PageBase):
             url_info = urlparse(url)
             hostname = url_info.hostname
             path = url_info.path
-            port = url_info.port or 80
+            port = url_info.port or (443 if url_info.scheme == 'https' else 80)
             scheme = url_info.scheme
         else:
             # Cannot determine a URL to this page - cobble one together based on
diff --git a/wagtail/core/tests/test_page_model.py b/wagtail/core/tests/test_page_model.py
index 71add730e2..935f3a3c27 100644
--- a/wagtail/core/tests/test_page_model.py
+++ b/wagtail/core/tests/test_page_model.py
@@ -1364,6 +1364,31 @@ class TestDummyRequest(TestCase):
         self.assertIn('wsgi.multiprocess', request.META)
         self.assertIn('wsgi.run_once', request.META)
 
+    def test_dummy_request_for_accessible_page_https(self):
+        Site.objects.update(port=443)
+
+        event_index = Page.objects.get(url_path='/home/events/')
+        request = event_index.dummy_request()
+
+        # request should have the correct path and hostname for this page
+        self.assertEqual(request.path, '/events/')
+        self.assertEqual(request.META['HTTP_HOST'], 'localhost')
+
+        # check other env vars required by the WSGI spec
+        self.assertEqual(request.META['REQUEST_METHOD'], 'GET')
+        self.assertEqual(request.META['SCRIPT_NAME'], '')
+        self.assertEqual(request.META['PATH_INFO'], '/events/')
+        self.assertEqual(request.META['SERVER_NAME'], 'localhost')
+        self.assertEqual(request.META['SERVER_PORT'], 443)
+        self.assertEqual(request.META['SERVER_PROTOCOL'], 'HTTP/1.1')
+        self.assertEqual(request.META['wsgi.version'], (1, 0))
+        self.assertEqual(request.META['wsgi.url_scheme'], 'https')
+        self.assertIn('wsgi.input', request.META)
+        self.assertIn('wsgi.errors', request.META)
+        self.assertIn('wsgi.multithread', request.META)
+        self.assertIn('wsgi.multiprocess', request.META)
+        self.assertIn('wsgi.run_once', request.META)
+
     def test_dummy_request_for_accessible_page_with_original_request(self):
         event_index = Page.objects.get(url_path='/home/events/')
         original_headers = {