diff --git a/.github/workflows/siibra-testing.yml b/.github/workflows/siibra-testing.yml
index 2fd16f26..53c92177 100644
--- a/.github/workflows/siibra-testing.yml
+++ b/.github/workflows/siibra-testing.yml
@@ -47,32 +47,20 @@ jobs:
     needs: "use-custom-cfg"
     uses: ./.github/workflows/_importable.yaml
     with:
-      os: ubuntu-latest
+      os: ubuntu-20.04  # use ubuntu-latest when python 3.7 is dropped
       python-version: ${{ matrix.python-version }}
       use-cfg: ${{ needs.use-custom-cfg.outputs.USE_REF }}
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.12", "3.11", "3.10", "3.9", "3.8"]
-
-  check-importable-python-3_7:
-    needs: "use-custom-cfg"
-    uses: ./.github/workflows/_importable.yaml
-    with:
-      os: ubuntu-20.04
-      python-version: ${{ matrix.python-version }}
-      use-cfg: ${{ needs.use-custom-cfg.outputs.USE_REF }}
-    strategy:
-      fail-fast: false
-      matrix:
-        python-version: ["3.7"]
+        python-version: ["3.12", "3.11", "3.10", "3.9", "3.8", "3.7"]
 
   unit-tests-full:
     if: ${{ github.event_name == 'pull_request' }}
     needs: "use-custom-cfg"
     uses: ./.github/workflows/_unittest.yaml
     with:
-      os: ubuntu-latest
+      os: ubuntu-20.04  # use ubuntu-latest when python 3.7 is dropped
       python-version: ${{ matrix.python-version }}
       use-cfg: ${{ needs.use-custom-cfg.outputs.USE_REF }}
     strategy:
@@ -94,7 +82,7 @@ jobs:
     needs: "use-custom-cfg"
     uses: ./.github/workflows/_e2e.yaml
     with:
-      os: ubuntu-latest
+      os: ubuntu-20.04  # use ubuntu-latest when python 3.7 is dropped
       python-version: ${{ matrix.python-version }}
       use-cfg: ${{ needs.use-custom-cfg.outputs.USE_REF }}
     strategy: