diff --git a/docs/en_US/release_notes_4_16.rst b/docs/en_US/release_notes_4_16.rst
index dc92d0c9c..74b4f7b9d 100644
--- a/docs/en_US/release_notes_4_16.rst
+++ b/docs/en_US/release_notes_4_16.rst
@@ -38,3 +38,4 @@ Bug fixes
 | `Issue #4935 <https://redmine.postgresql.org/issues/4935>`_ -  Fix accessibility issues.
 | `Issue #4964 <https://redmine.postgresql.org/issues/4964>`_ -  Fix an issue where length and precision are not removed from table/column dialog.
 | `Issue #4965 <https://redmine.postgresql.org/issues/4965>`_ -  Fix an issue where the Interval data type is not displayed in the properties dialog of table/column.
+| `Issue #4978 <https://redmine.postgresql.org/issues/4978>`_ -  Fix pgAdmin4 failed to start issue after upgrading to version 4.15.
diff --git a/web/pgAdmin4.py b/web/pgAdmin4.py
index 845ca52aa..4668458f0 100644
--- a/web/pgAdmin4.py
+++ b/web/pgAdmin4.py
@@ -69,6 +69,7 @@ if not os.path.isfile(config.SQLITE_PATH):
 ##########################################################################
 class ReverseProxied(object):
     def __init__(self, app):
+        self.app = app
         # https://werkzeug.palletsprojects.com/en/0.15.x/middleware/proxy_fix/#module-werkzeug.middleware.proxy_fix
         try:
             from werkzeug.middleware.proxy_fix import ProxyFix