diff --git a/.gitea/workflows/ci.yml b/.gitea/workflows/ci.yml
index 0685c3c..4278d5f 100644
--- a/.gitea/workflows/ci.yml
+++ b/.gitea/workflows/ci.yml
@@ -21,9 +21,12 @@ jobs:
       - uses: actions/checkout@v4
       - name: Install + run tests
         run: |
-          python3 -m pip install --quiet --upgrade pip
-          python3 -m pip install --quiet -r requirements.txt pytest
-          python3 -m pytest -q
+          # Runner image's system Python is PEP 668 externally-managed, so use a venv.
+          python3 -m venv .venv
+          . .venv/bin/activate
+          pip install --quiet --upgrade pip
+          pip install --quiet -r requirements.txt pytest
+          pytest -q
 
   build-push:
     needs: test