diff --git a/.github/workflows/python-package.yml b/.github/workflows/python-package.yml
index d74df9ce67..7577092f3f 100644
--- a/.github/workflows/python-package.yml
+++ b/.github/workflows/python-package.yml
@@ -68,12 +68,15 @@ jobs:
       shell: "bash -l {0}"
       env:
         COVERAGE_FILE: .coverage.${{matrix.python-version}}.${{matrix.numpy_version}}
-        ZARR_TEST_ABS: 1
         ZARR_TEST_MONGO: 1
         ZARR_TEST_REDIS: 1
         ZARR_V3_EXPERIMENTAL_API: 1
         ZARR_V3_SHARDING: 1
       run: |
+        # Skip ABS on 3.9, see https://github.com/zarr-developers/zarr-python/pull/1542/#issuecomment-1945557365 etc.
+        if [[ "${{ matrix.python-version }}" == '3.9' ]]; then
+            export PYTEST_ADDOPTS="-k 'not test_s3'"
+        fi
         conda activate zarr-env
         mkdir ~/blob_emulator
         azurite -l ~/blob_emulator --debug debug.log 2>&1 > stdouterr.log &
diff --git a/.github/workflows/windows-testing.yml b/.github/workflows/windows-testing.yml
index 0ef7f21758..c2786df094 100644
--- a/.github/workflows/windows-testing.yml
+++ b/.github/workflows/windows-testing.yml
@@ -16,7 +16,7 @@ jobs:
     strategy:
       fail-fast: True
       matrix:
-        python-version: ['3.10', '3.11']
+        python-version: ['3.9', '3.10', '3.11']
     steps:
       - uses: actions/checkout@v4
         with:
@@ -45,12 +45,15 @@ jobs:
       - name: Run Tests
         shell: bash -l {0}
         run: |
+          # Skip ABS on 3.9, see https://github.com/zarr-developers/zarr-python/pull/1542/#issuecomment-1945557365 etc.
+          if [[ "${{ matrix.python-version }}" == '3.9' ]]; then
+            export PYTEST_ADDOPTS="-k 'not test_s3'"
+          fi
           conda activate zarr-env
           mkdir ~/blob_emulator
           azurite -l ~/blob_emulator --debug debug.log 2>&1 > stdouterr.log &
           pytest -sv --timeout=300
         env:
-          ZARR_TEST_ABS: 1
           ZARR_V3_EXPERIMENTAL_API: 1
           ZARR_V3_SHARDING: 1
       - name: Conda info
diff --git a/requirements_dev_optional.txt b/requirements_dev_optional.txt
index 0ac4922ce1..18c6a45a76 100644
--- a/requirements_dev_optional.txt
+++ b/requirements_dev_optional.txt
@@ -7,7 +7,7 @@ ipywidgets==8.1.1
 # optional library requirements for services
 # don't let pyup change pinning for azure-storage-blob, need to pin to older
 # version to get compatibility with azure storage emulator on appveyor (FIXME)
-azure-storage-blob==12.16.0 # pyup: ignore
+azure-storage-blob==12.18.3 # pyup: ignore
 redis==5.0.1
 types-redis
 types-setuptools