diff --git a/CHANGES.rst b/CHANGES.rst
index 32dfdd65..dddddbdc 100644
--- a/CHANGES.rst
+++ b/CHANGES.rst
@@ -1,5 +1,15 @@
 .. currentmodule:: flask
 
+Version 1.1.1
+-------------
+
+Released 2019-07-08
+
+-   The ``flask.json_available`` flag was added back for compatibility
+    with some extensions. It will raise a deprecation warning when used,
+    and will be removed in version 2.0.0. :issue:`3288`
+
+
 Version 1.1.0
 -------------
 
diff --git a/README.rst b/README.rst
index 6e574323..ecfccedb 100644
--- a/README.rst
+++ b/README.rst
@@ -66,8 +66,8 @@ donate today`_.
 Links
 -----
 
-* Website: https://www.palletsprojects.com/p/flask/
-* Documentation: http://flask.pocoo.org/docs/
+* Website: https://palletsprojects.com/p/flask/
+* Documentation: https://flask.palletsprojects.com/
 * Releases: https://pypi.org/project/Flask/
 * Code: https://github.com/pallets/flask
 * Issue tracker: https://github.com/pallets/flask/issues
diff --git a/setup.py b/setup.py
index fa680a75..8a0b8ad4 100644
--- a/setup.py
+++ b/setup.py
@@ -15,7 +15,7 @@ setup(
     version=version,
     url="https://palletsprojects.com/p/flask/",
     project_urls={
-        "Documentation": "http://flask.palletsprojects.com/",
+        "Documentation": "https://flask.palletsprojects.com/",
         "Code": "https://github.com/pallets/flask",
         "Issue tracker": "https://github.com/pallets/flask/issues",
     },
diff --git a/src/flask/__init__.py b/src/flask/__init__.py
index 7f5013e5..687475bc 100644
--- a/src/flask/__init__.py
+++ b/src/flask/__init__.py
@@ -17,6 +17,7 @@ from werkzeug.exceptions import abort
 from werkzeug.utils import redirect
 
 from . import json
+from ._compat import json_available
 from .app import Flask
 from .app import Request
 from .app import Response
@@ -56,4 +57,4 @@ from .signals import template_rendered
 from .templating import render_template
 from .templating import render_template_string
 
-__version__ = "1.1.0"
+__version__ = "1.1.1"
diff --git a/src/flask/_compat.py b/src/flask/_compat.py
index ee47d821..76c442ca 100644
--- a/src/flask/_compat.py
+++ b/src/flask/_compat.py
@@ -113,3 +113,33 @@ except ImportError:
     # https://www.python.org/dev/peps/pep-0519/#backwards-compatibility
     def fspath(path):
         return path.__fspath__() if hasattr(path, "__fspath__") else path
+
+
+class _DeprecatedBool(object):
+    def __init__(self, name, version, value):
+        self.message = "'{}' is deprecated and will be removed in version {}.".format(
+            name, version
+        )
+        self.value = value
+
+    def _warn(self):
+        import warnings
+
+        warnings.warn(self.message, DeprecationWarning, stacklevel=2)
+
+    def __eq__(self, other):
+        self._warn()
+        return other == self.value
+
+    def __ne__(self, other):
+        self._warn()
+        return other != self.value
+
+    def __bool__(self):
+        self._warn()
+        return self.value
+
+    __nonzero__ = __bool__
+
+
+json_available = _DeprecatedBool("flask.json_available", "2.0.0", True)
diff --git a/tests/test_deprecations.py b/tests/test_deprecations.py
new file mode 100644
index 00000000..523ec109
--- /dev/null
+++ b/tests/test_deprecations.py
@@ -0,0 +1,12 @@
+import pytest
+
+from flask import json_available
+
+
+def test_json_available():
+    with pytest.deprecated_call() as rec:
+        assert json_available
+        assert json_available == True  # noqa E712
+        assert json_available != False  # noqa E712
+
+    assert len(rec.list) == 3