diff --git a/.github/workflows/python-somacore.yaml b/.github/workflows/python-somacore.yaml
index f27d6c70..ee3d982f 100644
--- a/.github/workflows/python-somacore.yaml
+++ b/.github/workflows/python-somacore.yaml
@@ -12,7 +12,7 @@ jobs:
   format-check:
     runs-on: ubuntu-latest
     env:
-      PYTHON_VERSION: "3.8"
+      PYTHON_VERSION: "3.9"
     steps:
       - uses: actions/checkout@v3
 
@@ -20,11 +20,11 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           cache: pip
-          cache-dependency-path: python-spec/requirements-py${{ env.PYTHON_VERSION }}-lint.txt
+          cache-dependency-path: "python-spec/requirements-py${{ env.PYTHON_VERSION }}*.txt"
 
       - name: Install static analysis packages
-        run: |
-          pip install -r python-spec/requirements-py${{ env.PYTHON_VERSION }}-lint.txt
+        working-directory: python-spec
+        run: pip install -r requirements-py${PYTHON_VERSION}.txt -r requirements-py${PYTHON_VERSION}-lint.txt
 
       - name: Restore pre-commit cache
         uses: actions/cache@v3
@@ -45,7 +45,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: ["3.8", "3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
     steps:
       - uses: actions/checkout@v3
         with:
diff --git a/pyproject.toml b/pyproject.toml
index 1cf68cc6..63c415fa 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -24,7 +24,7 @@ dependencies = [
   "scipy",
   "typing-extensions>=4.1", # For LiteralString (py3.11)
 ]
-requires-python = "~=3.8"
+requires-python = ">=3.9"
 urls = { repository = "https://github.com/single-cell-data/SOMA.git" }
 classifiers = ["License :: OSI Approved :: MIT License"]
 
@@ -43,7 +43,7 @@ tag_regex = '^python-(?P<version>[vV]?\d+(?:\.\d+){0,2}[^\+]*)(?:\+.*)?$'
 
 [tool.ruff]
 lint.extend-select = ["I"]
-target-version = "py38"
+target-version = "py39"
 
 [tool.ruff.lint.isort]
 force-single-line = true
@@ -54,7 +54,7 @@ single-line-exclusions = ["typing", "typing_extensions"]
 check_untyped_defs = true
 enable_error_code = ["ignore-without-code"]
 warn_redundant_casts = true
-python_version = 3.8
+python_version = 3.9
 # We want to enable this but it won't work when running locally due to the
 # presence of _version.py (which invalidates the ignore, which causes an error).
 #
diff --git a/python-spec/requirements-py3.8-lint.txt b/python-spec/requirements-py3.8-lint.txt
deleted file mode 100644
index 62af1603..00000000
--- a/python-spec/requirements-py3.8-lint.txt
+++ /dev/null
@@ -1,38 +0,0 @@
-anndata==0.9.2
-attrs==23.2.0
-black==24.4.2
-cfgv==3.4.0
-click==8.1.7
-distlib==0.3.8
-filelock==3.15.1
-h5py==3.11.0
-identify==2.5.36
-importlib_metadata==7.1.0
-isort==5.13.2
-llvmlite==0.41.1
-mypy==1.10.0
-mypy-extensions==1.0.0
-natsort==8.4.0
-nodeenv==1.9.1
-numba==0.58.1
-numpy==1.24.4
-packaging==24.1
-pandas==2.0.3
-pandas-stubs==2.0.3.230814
-pathspec==0.12.1
-platformdirs==4.2.2
-pre-commit==3.5.0
-pyarrow==16.1.0
-pyarrow-hotfix==0.6
-python-dateutil==2.9.0.post0
-pytz==2024.1
-PyYAML==6.0.1
-ruff==0.4.9
-scipy==1.10.1
-six==1.16.0
-tomli==2.0.1
-types-pytz==2024.1.0.20240417
-typing_extensions==4.12.2
-tzdata==2024.1
-virtualenv==20.26.2
-zipp==3.19.2
diff --git a/python-spec/requirements-py3.8.txt b/python-spec/requirements-py3.8.txt
deleted file mode 100644
index 7da2b9f5..00000000
--- a/python-spec/requirements-py3.8.txt
+++ /dev/null
@@ -1,19 +0,0 @@
-anndata==0.9.2
-attrs==23.2.0
-h5py==3.11.0
-importlib_metadata==7.1.0
-llvmlite==0.41.1
-natsort==8.4.0
-numba==0.58.1
-numpy==1.24.4
-packaging==24.1
-pandas==2.0.3
-pyarrow==16.1.0
-pyarrow-hotfix==0.6
-python-dateutil==2.9.0.post0
-pytz==2024.1
-scipy==1.10.1
-six==1.16.0
-typing_extensions==4.12.2
-tzdata==2024.1
-zipp==3.19.2
diff --git a/python-spec/requirements-py3.9-lint.txt b/python-spec/requirements-py3.9-lint.txt
new file mode 100644
index 00000000..aef1a068
--- /dev/null
+++ b/python-spec/requirements-py3.9-lint.txt
@@ -0,0 +1,3 @@
+mypy==1.11.2
+pandas-stubs==2.2.2.240807  # last version which supports Python 3.9
+pre-commit==3.8.0
diff --git a/python-spec/src/somacore/coordinates.py b/python-spec/src/somacore/coordinates.py
index 986ed83e..83555e88 100644
--- a/python-spec/src/somacore/coordinates.py
+++ b/python-spec/src/somacore/coordinates.py
@@ -26,9 +26,7 @@ class Axis:
 
 
 @attrs.define(frozen=True)
-class CoordinateSpace(
-    collections.abc.Sequence
-):  # Change to Sequence[Axis] after 3.8 is dropped.
+class CoordinateSpace(collections.abc.Sequence):
     """A coordinate space for spatial data.
 
     Args:
@@ -37,7 +35,7 @@ class CoordinateSpace(
     Lifecycle: experimental
     """
 
-    axes: Tuple[Axis, ...] = attrs.field(converter=tuple)
+    axes: Sequence[Axis] = attrs.field(converter=tuple)
 
     @axes.validator
     def _validate(self, _, axes: Tuple[Axis, ...]) -> None:
diff --git a/python-spec/update-requirements-txt b/python-spec/update-requirements-txt
index 172bee02..42f9b88a 100755
--- a/python-spec/update-requirements-txt
+++ b/python-spec/update-requirements-txt
@@ -10,9 +10,9 @@ TEMPDIR="$(mktemp -d)"
 trap "trash $TEMPDIR" EXIT
 
 # The version of Python we want to run lints under.
-LINTVER=3.8
+LINTVER=3.9
 
-for PYVER in 3.8 3.9 3.10 3.11 3.12; do
+for PYVER in 3.9 3.10 3.11 3.12; do
   CONDIR="$TEMPDIR/py-$PYVER"
   conda create -y -p "$CONDIR" "python=$PYVER"
   (