diff --git a/scrapy/core/downloader/handlers/http2.py b/scrapy/core/downloader/handlers/http2.py
index 650af9778..f2ed40f9b 100644
--- a/scrapy/core/downloader/handlers/http2.py
+++ b/scrapy/core/downloader/handlers/http2.py
@@ -71,8 +71,8 @@ class ScrapyH2Agent:
 
     def __init__(
         self, context_factory,
-        connect_timeout=10,
-        bind_address: Optional[bytes] = None, pool: H2ConnectionPool = None,
+        pool: H2ConnectionPool,
+        connect_timeout=10, bind_address: Optional[bytes] = None,
         crawler=None
     ) -> None:
         self._context_factory = context_factory
diff --git a/scrapy/core/http2/protocol.py b/scrapy/core/http2/protocol.py
index 1ce8b6548..fee391af6 100644
--- a/scrapy/core/http2/protocol.py
+++ b/scrapy/core/http2/protocol.py
@@ -323,7 +323,7 @@ class H2ClientProtocol(Protocol, TimeoutMixin):
             elif isinstance(event, SettingsAcknowledged):
                 self.settings_acknowledged(event)
             elif isinstance(event, UnknownFrameReceived):
-                logger.debug(f'UnknownFrameReceived: frame={event.frame}')
+                logger.debug('UnknownFrameReceived: frame={}'.format(event.frame))
 
     # Event handler functions starts here
     def connection_terminated(self, event: ConnectionTerminated) -> None:
diff --git a/setup.cfg b/setup.cfg
index f8e7c0c91..8b70a0e60 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -100,6 +100,9 @@ ignore_errors = True
 [mypy-tests.test_downloader_handlers]
 ignore_errors = True
 
+[mypy-tests.test_download_handlers_http2]
+ignore_errors = True
+
 [mypy-tests.test_engine]
 ignore_errors = True
 
@@ -109,6 +112,9 @@ ignore_errors = True
 [mypy-tests.test_http_request]
 ignore_errors = True
 
+[mypy-tests.test_http2_client_protocol]
+ignore_errors = True
+
 [mypy-tests.test_linkextractors]
 ignore_errors = True