diff --git a/tests/test_downloadermiddleware_httpproxy.py b/tests/test_downloadermiddleware_httpproxy.py
index ca125ba36..0040f8d23 100644
--- a/tests/test_downloadermiddleware_httpproxy.py
+++ b/tests/test_downloadermiddleware_httpproxy.py
@@ -14,7 +14,7 @@ spider = Spider("foo")
 
 class TestHttpProxyMiddleware(TestCase):
 
-    failureException = AssertionError
+    failureException = AssertionError  # type: ignore[assignment]
 
     def setUp(self):
         self._oldenv = os.environ.copy()
diff --git a/tests/test_http2_client_protocol.py b/tests/test_http2_client_protocol.py
index 88345d2bc..2a928eea0 100644
--- a/tests/test_http2_client_protocol.py
+++ b/tests/test_http2_client_protocol.py
@@ -5,6 +5,7 @@ import shutil
 import string
 from ipaddress import IPv4Address
 from pathlib import Path
+from typing import Dict
 from unittest import mock, skipIf
 from urllib.parse import urlencode
 
@@ -86,6 +87,7 @@ class GetDataHtmlLarge(LeafResource):
 class PostDataJsonMixin:
     @staticmethod
     def make_response(request: TxRequest, extra_data: str):
+        assert request.content is not None
         response = {
             "request-headers": {},
             "request-body": json.loads(request.content.read()),
@@ -144,7 +146,8 @@ class QueryParams(LeafResource):
         request.setHeader("Content-Type", "application/json; charset=UTF-8")
         request.setHeader("Content-Encoding", "UTF-8")
 
-        query_params = {}
+        query_params: Dict[str, str] = {}
+        assert request.args is not None
         for k, v in request.args.items():
             query_params[str(k, "utf-8")] = str(v[0], "utf-8")
 
diff --git a/tests/test_spidermiddleware.py b/tests/test_spidermiddleware.py
index 760ee43df..ca6348913 100644
--- a/tests/test_spidermiddleware.py
+++ b/tests/test_spidermiddleware.py
@@ -112,6 +112,7 @@ class BaseAsyncSpiderMiddlewareTestCase(SpiderMiddlewareTestCase):
     Should work for process_spider_output and, when it's supported, process_start_requests.
     """
 
+    ITEM_TYPE: type
     RESULT_COUNT = 3  # to simplify checks, let everything return 3 objects
 
     @staticmethod