diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2c265c0d8..41b478bd7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -9,6 +9,7 @@ on:
 
 env:
   PYTEST_ADDOPTS: "--color=yes"
+  LINTING_PY_VERSION: "3.9"  # The version of Python to use for linting (typically the minimum supported)
 
 # Cancel running workflows when additional changes are pushed
 # https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#example-using-a-fallback-value
@@ -26,10 +27,10 @@ jobs:
       with:
         submodules: true
 
-    - name: Set up Python 3.9
+    - name: Set up Python ${{ env.LINTING_PY_VERSION }}
       uses: actions/setup-python@v4
       with:
-        python-version: '3.9'
+        python-version: ${{ env.LINTING_PY_VERSION }}
         cache: 'pip'
         cache-dependency-path: |
           requirements*.txt
@@ -56,10 +57,10 @@ jobs:
       with:
         submodules: true
 
-    - name: Set up Python 3.9
+    - name: Set up Python ${{ env.LINTING_PY_VERSION }}
       uses: actions/setup-python@v4
       with:
-        python-version: '3.9'
+        python-version: ${{ env.LINTING_PY_VERSION }}
         cache: 'pip'
         cache-dependency-path: |
           requirements*.txt
@@ -184,25 +185,25 @@ jobs:
         pip install -r requirements-http-client.txt
 
     - name: Run non-server tests
-      run: pytest -rs -vvv --cov=./optimade/ --cov-report=xml tests/ --ignore tests/server
+      run: pytest -rs -vvv --durations=0 --cov=./optimade/ --cov-report=xml tests/ --ignore tests/server
 
     - name: Install latest server dependencies
       run: pip install -r requirements-server.txt
 
     - name: Run server tests (using `mongomock`)
-      run: pytest -rs -vvv --cov=./optimade/ --cov-report=xml --cov-append tests/server tests/filtertransformers
+      run: pytest -rs -vvv --durations=0 --cov=./optimade/ --cov-report=xml --cov-append tests/server tests/filtertransformers
       env:
         OPTIMADE_DATABASE_BACKEND: 'mongomock'
 
     - name: Run server tests with no API validation (using `mongomock`)
       run:
-        pytest -rs -vvv --cov=./optimade/ --cov-report=xml --cov-append tests/server tests/filtertransformers
+        pytest -rs -vvv --durations=0 --cov=./optimade/ --cov-report=xml --cov-append tests/server tests/filtertransformers
       env:
         OPTIMADE_DATABASE_BACKEND: 'mongomock'
         OPTIMADE_VALIDATE_API_RESPONSE: false
 
     - name: Run server tests (using a real MongoDB)
-      run: pytest -rs -vvv --cov=./optimade/ --cov-report=xml --cov-append tests/server tests/filtertransformers
+      run: pytest -rs -vvv --durations=0 --cov=./optimade/ --cov-report=xml --cov-append tests/server tests/filtertransformers
       env:
         OPTIMADE_DATABASE_BACKEND: 'mongodb'
 
@@ -227,36 +228,38 @@ jobs:
       run: pytest -rs -vvv --cov=./optimade/ --cov-report=xml --cov-append tests/adapters/
 
     - name: Run tests for validator only to assess coverage (mongomock)
-      if: matrix.python-version == 3.9
+      if: matrix.python-version == '3.11'
       run: pytest -rs --cov=./optimade/ --cov-report=xml:validator_cov.xml --cov-append tests/server/test_server_validation.py
       env:
         OPTIMADE_DATABASE_BACKEND: 'mongomock'
 
     - name: Run tests for validator only to assess coverage (Elasticsearch)
-      if: matrix.python-version == 3.9
+      if: matrix.python-version == '3.11'
       run: pytest -rs --cov=./optimade/ --cov-report=xml:validator_cov.xml --cov-append tests/server/test_server_validation.py
       env:
         OPTIMADE_DATABASE_BACKEND: 'elastic'
         OPTIMADE_INSERT_TEST_DATA: false # Must be specified as previous steps will have already inserted the test data
 
     - name: Run tests for validator only to assess coverage (MongoDB)
-      if: matrix.python-version == 3.9
+      if: matrix.python-version == '3.11'
       run: pytest -rs --cov=./optimade/ --cov-report=xml:validator_cov.xml --cov-append tests/server/test_server_validation.py
       env:
         OPTIMADE_DATABASE_BACKEND: 'mongodb'
         OPTIMADE_INSERT_TEST_DATA: false # Must be specified as previous steps will have already inserted the test data
 
     - name: Run the OPTIMADE Client CLI
-      if: matrix.python-version == 3.9
+      if: matrix.python-version == '3.11'
       run: |
         coverage run --append --source optimade optimade/client/cli.py \
            --filter 'nsites = 1' \
+           --http-timeout 1.0 \
            --output-file test_get_async.json \
            https://optimade.fly.dev
         test test_get_async.json
 
         coverage run --append --source optimade optimade/client/cli.py \
           --filter 'nsites = 1' \
+           --http-timeout 1.0 \
           --count \
           --output-file test_count.json \
           https://optimade.fly.dev
@@ -265,6 +268,7 @@ jobs:
         coverage run --append --source optimade optimade/client/cli.py \
           --no-async \
           --filter 'nsites = 1' \
+           --http-timeout 1.0 \
           --count \
           --output-file test_count_no_async.json \
           https://optimade.fly.dev
@@ -275,7 +279,7 @@ jobs:
         coverage xml
 
     - name: Upload coverage to Codecov
-      if: matrix.python-version == '3.9' && github.repository == 'Materials-Consortia/optimade-python-tools'
+      if: matrix.python-version == '3.11' && github.repository == 'Materials-Consortia/optimade-python-tools'
       uses: codecov/codecov-action@v3
       with:
         name: project
@@ -283,7 +287,7 @@ jobs:
         flags: project
 
     - name: Upload validator coverage to Codecov
-      if: matrix.python-version == '3.9' && github.repository == 'Materials-Consortia/optimade-python-tools'
+      if: matrix.python-version == '3.11' && github.repository == 'Materials-Consortia/optimade-python-tools'
       uses: codecov/codecov-action@v3
       with:
         name: validator
@@ -300,7 +304,7 @@ jobs:
 
     - uses: actions/setup-python@v4
       with:
-        python-version: '3.9'
+        python-version: ${{ env.LINTING_PY_VERSION }}
         cache: 'pip'
         cache-dependency-path: |
           requirements*.txt
@@ -330,10 +334,10 @@ jobs:
     - name: Checkout repository
       uses: actions/checkout@v4
 
-    - name: Set up Python 3.9
+    - name: Set up Python ${{ env.LINTING_PY_VERSION }}
       uses: actions/setup-python@v4
       with:
-        python-version: '3.9'
+        python-version: ${{ env.LINTING_PY_VERSION }}
         cache: 'pip'
         cache-dependency-path: |
           requirements*.txt