diff --git a/.azure-pipelines.yml b/.azure-pipelines.yml
index 243f8783..717b588e 100644
--- a/.azure-pipelines.yml
+++ b/.azure-pipelines.yml
@@ -10,7 +10,6 @@ jobs:
       python.architecture: 'x64'
       TOXENV: 'py,coverage-ci'
       publish.test.results: 'true'
-      CODECOV_TOKEN: '$(codecov.token)'
 
     strategy:
       matrix:
diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index eb797309..6d2a2f1f 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -1,6 +1,6 @@
 repos:
   - repo: https://github.com/asottile/reorder_python_imports
-    rev: v1.4.0
+    rev: v1.5.0
     hooks:
       - id: reorder-python-imports
         name: Reorder Python imports (src, tests)
diff --git a/src/flask/_compat.py b/src/flask/_compat.py
index b3876055..dfbb0cda 100644
--- a/src/flask/_compat.py
+++ b/src/flask/_compat.py
@@ -63,7 +63,7 @@ def with_metaclass(meta, *bases):
     # dummy metaclass for one level of class instantiation that replaces
     # itself with the actual metaclass.
     class metaclass(type):
-        def __new__(mcs, name, this_bases, d):
+        def __new__(metacls, name, this_bases, d):
             return meta(name, bases, d)
 
     return type.__new__(metaclass, "temporary_class", (), {})
diff --git a/tests/conftest.py b/tests/conftest.py
index 56688bb3..0ba687d5 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -6,7 +6,6 @@
     :copyright: © 2010 by the Pallets team.
     :license: BSD, see LICENSE for more details.
 """
-import gc
 import os
 import pkgutil
 import sys
@@ -201,10 +200,3 @@ def purge_module(request):
         request.addfinalizer(lambda: sys.modules.pop(name, None))
 
     return inner
-
-
-@pytest.fixture(autouse=True)
-def catch_deprecation_warnings(recwarn):
-    yield
-    gc.collect()
-    assert not recwarn.list, "\n".join(str(w.message) for w in recwarn.list)
diff --git a/tests/test_basic.py b/tests/test_basic.py
index 92214272..63f23a8d 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -1475,60 +1475,46 @@ def test_request_locals():
     assert not flask.g
 
 
-def test_test_app_proper_environ():
+def test_server_name_subdomain():
     app = flask.Flask(__name__, subdomain_matching=True)
-    app.config.update(SERVER_NAME="localhost.localdomain:5000")
     client = app.test_client()
 
     @app.route("/")
     def index():
-        return "Foo"
+        return "default"
 
     @app.route("/", subdomain="foo")
     def subdomain():
-        return "Foo SubDomain"
+        return "subdomain"
 
+    app.config["SERVER_NAME"] = "dev.local:5000"
     rv = client.get("/")
-    assert rv.data == b"Foo"
+    assert rv.data == b"default"
 
-    rv = client.get("/", "http://localhost.localdomain:5000")
-    assert rv.data == b"Foo"
+    rv = client.get("/", "http://dev.local:5000")
+    assert rv.data == b"default"
 
-    rv = client.get("/", "https://localhost.localdomain:5000")
-    assert rv.data == b"Foo"
+    rv = client.get("/", "https://dev.local:5000")
+    assert rv.data == b"default"
 
-    app.config.update(SERVER_NAME="localhost.localdomain")
-    rv = client.get("/", "https://localhost.localdomain")
-    assert rv.data == b"Foo"
+    app.config["SERVER_NAME"] = "dev.local:443"
+    rv = client.get("/", "https://dev.local")
 
-    try:
-        app.config.update(SERVER_NAME="localhost.localdomain:443")
-        rv = client.get("/", "https://localhost.localdomain")
-        # Werkzeug 0.8
-        assert rv.status_code == 404
-    except ValueError as e:
-        # Werkzeug 0.7
-        assert str(e) == (
-            "the server name provided "
-            "('localhost.localdomain:443') does not match the "
-            "server name from the WSGI environment ('localhost.localdomain')"
-        )
+    # Werkzeug 1.0 fixes matching https scheme with 443 port
+    if rv.status_code != 404:
+        assert rv.data == b"default"
 
-    try:
-        app.config.update(SERVER_NAME="localhost.localdomain")
+    app.config["SERVER_NAME"] = "dev.local"
+    rv = client.get("/", "https://dev.local")
+    assert rv.data == b"default"
+
+    # suppress Werkzeug 1.0 warning about name mismatch
+    with pytest.warns(None):
         rv = client.get("/", "http://foo.localhost")
-        # Werkzeug 0.8
         assert rv.status_code == 404
-    except ValueError as e:
-        # Werkzeug 0.7
-        assert str(e) == (
-            "the server name provided "
-            "('localhost.localdomain') does not match the "
-            "server name from the WSGI environment ('foo.localhost')"
-        )
 
-    rv = client.get("/", "http://foo.localhost.localdomain")
-    assert rv.data == b"Foo SubDomain"
+    rv = client.get("/", "http://foo.dev.local")
+    assert rv.data == b"subdomain"
 
 
 def test_exception_propagation(app, client):
@@ -1885,9 +1871,11 @@ def test_subdomain_matching_other_name(matching):
     def index():
         return "", 204
 
-    # ip address can't match name
-    rv = client.get("/", "http://127.0.0.1:3000/")
-    assert rv.status_code == 404 if matching else 204
+    # suppress Werkzeug 0.15 warning about name mismatch
+    with pytest.warns(None):
+        # ip address can't match name
+        rv = client.get("/", "http://127.0.0.1:3000/")
+        assert rv.status_code == 404 if matching else 204
 
     # allow all subdomains if matching is disabled
     rv = client.get("/", "http://www.localhost.localdomain:3000/")
diff --git a/tests/test_helpers.py b/tests/test_helpers.py
index cacbca2e..2b7c776f 100644
--- a/tests/test_helpers.py
+++ b/tests/test_helpers.py
@@ -455,7 +455,7 @@ class TestSendfile(object):
             assert rv.data == f.read()
         rv.close()
 
-    def test_send_file_xsendfile(self, app, req_ctx, catch_deprecation_warnings):
+    def test_send_file_xsendfile(self, app, req_ctx):
         app.use_x_sendfile = True
         rv = flask.send_file("static/index.html")
         assert rv.direct_passthrough
diff --git a/tests/test_reqctx.py b/tests/test_reqctx.py
index 20ae2b28..4013528c 100644
--- a/tests/test_reqctx.py
+++ b/tests/test_reqctx.py
@@ -89,17 +89,12 @@ def test_proper_test_request_context(app):
             == "http://foo.localhost.localdomain:5000/"
         )
 
-    try:
+    # suppress Werkzeug 0.15 warning about name mismatch
+    with pytest.warns(None):
         with app.test_request_context(
             "/", environ_overrides={"HTTP_HOST": "localhost"}
         ):
             pass
-    except ValueError as e:
-        assert str(e) == (
-            "the server name provided "
-            "('localhost.localdomain:5000') does not match the "
-            "server name from the WSGI environment ('localhost')"
-        )
 
     app.config.update(SERVER_NAME="localhost")
     with app.test_request_context("/", environ_overrides={"SERVER_NAME": "localhost"}):
diff --git a/tox.ini b/tox.ini
index 2be290a1..63dda527 100644
--- a/tox.ini
+++ b/tox.ini
@@ -33,7 +33,7 @@ commands =
     pip install -q -e examples/javascript[test]
 
     # pytest-cov doesn't seem to play nice with -p
-    coverage run -p -m pytest --tb=short {posargs:tests examples}
+    coverage run -p -m pytest --tb=short -Werror {posargs:tests examples}
 
 [testenv:nightly]
 # courtesy Python nightly test, don't fail the build in CI
@@ -41,7 +41,7 @@ ignore_outcome = true
 commands =
     pip install -q -e examples/tutorial[test]
     pip install -q -e examples/javascript[test]
-    coverage run -p -m pytest --tb=short --junitxml=test-results.xml {posargs:tests examples}
+    coverage run -p -m pytest --tb=short -Werror --junitxml=test-results.xml {posargs:tests examples}
 
 [testenv:stylecheck]
 deps = pre-commit
@@ -62,13 +62,9 @@ commands =
     coverage report
 
 [testenv:coverage-ci]
-passenv = CODECOV_TOKEN
-deps =
-    coverage
-    codecov
+deps = coverage
 skip_install = true
 commands =
     coverage combine
-    codecov
     coverage xml
     coverage report