diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 073c4458c..950eb868e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -474,7 +474,7 @@ jobs:
     - name: Set up Python
       uses: actions/setup-python@v4
       with:
-        python-version: 3.9
+        python-version: 3.11
     - name: Install flake8
       run: pip install flake8
     - name: Run flake8
diff --git a/test/test_downloader_fragment.py b/test/test_downloader_fragment.py
index 62a28ec92..8dbf6e78d 100644
--- a/test/test_downloader_fragment.py
+++ b/test/test_downloader_fragment.py
@@ -13,7 +13,10 @@ sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 from test.helper import FakeLogger, http_server_port
 from youtube_dl import YoutubeDL
-from youtube_dl.compat import compat_http_server
+from youtube_dl.compat import (
+    compat_http_server,
+    compat_str as str,
+)
 from youtube_dl.downloader.dash import DashSegmentsFD