diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c432db0f..f458201d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -41,7 +41,7 @@ jobs:
       name: Unit tests and coverage (ubuntu-latest, macos-latest)
       run: |
         pyver=`echo ${{ matrix.python-version }} | tr -d "."`
-        tox -e py${pyver} -- -m 'not e2e'
+        tox -e py${pyver} -- -m 'not e2e' -m 'not not_on_ci'
         tox -e py${pyver}-nb
     - if: matrix.os == 'windows-latest'
       name: Unit tests and coverage (windows-latest)
diff --git a/pytest.ini b/pytest.ini
index be5c67a1..44492cca 100644
--- a/pytest.ini
+++ b/pytest.ini
@@ -6,3 +6,4 @@ log_cli_date_format=%Y-%m-%d %H:%M:%S
 
 markers =
     e2e: marks end-to-end tests which involve several library components.
+    not_on_ci: marks tests as not suitable for CI.