diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 9e4a2561..f29c4d07 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -19,8 +19,8 @@ jobs:
       fail-fast: false
       matrix:
         os: [ubuntu-latest]
-        python-version: ["3.10", "3.11", "3.12", "3.13"]
-        sphinx: ["~=8.0"]  # temporary limit, bring it back to newest sphinx once we are sphinx9 compatible
+        python-version: ["3.11", "3.12", "3.13", "3.14"]
+        sphinx: [""]  # Newest Sphinx
         myst-parser: [""]  # Newest MyST Parser (any)
         include:
           # Just check the other platforms once
@@ -39,6 +39,12 @@ jobs:
             sphinx: "~=8.0"
             myst-parser: "~=4.0"
             pillow: "==11.0.0"
+          # Oldest known-compatible dependencies
+          - os: ubuntu-latest
+            python-version: "3.10"
+            sphinx: "==5.0.0"
+            myst-parser: "==1.0.0"
+            pillow: "==11.0.0"
           # Mid-range dependencies
           - os: ubuntu-latest
             python-version: "3.11"
@@ -47,9 +53,9 @@ jobs:
             pillow: "==11.0.0"
           # Newest known-compatible dependencies
           - os: ubuntu-latest
-            python-version: "3.13"
-            sphinx: "~=8.0"
-            myst-parser: "==4.0.0"
+            python-version: "3.14"
+            sphinx: "~=9.0"
+            myst-parser: "~=5.0"
             pillow: "==11.0.0"
 
     runs-on: ${{ matrix.os }}
@@ -71,42 +77,9 @@ jobs:
     - name: Run pytest
       run: pytest --durations=10
 
-  coverage:
-    needs: [tests]
-    runs-on: ubuntu-latest
-
-    steps:
-    - uses: actions/checkout@v6
-    - name: Set up Python ${{ matrix.python-version }}
-      uses: actions/setup-python@v6
-      with:
-        python-version: "3.11"
-        cache: pip
-    - name: Install dependencies
-      run: |
-        pip install -e .[testing]
-        pip freeze
-
-    - name: Run pytest
-      run: pytest --durations=10 --cov=myst_nb --cov-report=xml --cov-report=term-missing
-
-    - name: Create cov
-      run: coverage xml
-      # for some reason the tests/conftest.py::check_nbs fixture breaks pytest-cov's cov-report outputting
-      # this is why we run `coverage xml` afterwards (required by codecov)
-
-    # TEMPORARY FIX: Disable codecov until we can get it working again
-    - name: Upload to Codecov
-      uses: codecov/codecov-action@v5
-      if: false
-      with:
-        name: myst-nb-pytests
-        flags: pytests
-        files: ./coverage.xml
-
   publish:
 
-    name: Publish to PyPi
+    name: Publish to PyPI
     needs: [tests]
     if: github.event_name == 'push' && startsWith(github.event.ref, 'refs/tags')
     runs-on: ubuntu-latest
diff --git a/myst_nb/sphinx_ext.py b/myst_nb/sphinx_ext.py
index 1a61ef78..9a7b7996 100644
--- a/myst_nb/sphinx_ext.py
+++ b/myst_nb/sphinx_ext.py
@@ -7,7 +7,6 @@
 from importlib import resources as import_resources
 import os
 from pathlib import Path
-import sys
 from types import ModuleType
 from typing import Any, Iterator, cast
 
@@ -194,14 +193,10 @@ def _get_file_hash(path: Path):
 
 @contextlib.contextmanager
 def _import_resources_path(package: ModuleType, resource: str) -> Iterator[Path]:
-    if sys.version_info < (3, 9):
-        with import_resources.path(package, resource) as path:
-            yield path
-    else:
-        with import_resources.as_file(
-            import_resources.files(package).joinpath(resource)
-        ) as path:
-            yield path
+    with import_resources.as_file(
+        import_resources.files(package).joinpath(resource)
+    ) as path:
+        yield path
 
 
 def add_css(app: Sphinx):
diff --git a/pyproject.toml b/pyproject.toml
index c0ac0ea4..11d0a6b5 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,4 +1,4 @@
- [build-system]
+[build-system]
 requires = ["flit_core >=3.11,<4"]
 build-backend = "flit_core.buildapi"
 
@@ -20,6 +20,7 @@ classifiers = [
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
     "Programming Language :: Python :: Implementation :: CPython",
     "Programming Language :: Python :: Implementation :: PyPy",
     "Topic :: Software Development :: Libraries :: Python Modules",
@@ -42,7 +43,7 @@ dependencies = [
     "myst-parser>=1.0.0",
     "nbformat>=5.0",
     "pyyaml",
-    "sphinx>=5,<9",  # If we get bugs for older versions, just pin this higher
+    "sphinx>=5",  # If we get bugs for older versions, just pin this higher
     "typing-extensions",
     # ipykernel is not a requirement of the library,
     # but is a common requirement for users (registers the python3 kernel)
@@ -174,8 +175,8 @@ filterwarnings = [
     'ignore:datetime.datetime.utcnow\(\) is deprecated:DeprecationWarning:jupyter_cache',
     # From matplotlib’s dependencies
     'ignore::DeprecationWarning:pyparsing',  # imports deprecated `sre_constants`
-    # From myst-parser on Sphinx 9
-    'ignore:.*MystReferenceResolver.app.*:DeprecationWarning',
+    # From myst-parser on Sphinx 9 we hit RemovedInSphinx11Warning
+    'ignore:.*MystReferenceResolver.app.*',
     # Upstream myst-parser still hits env.app deprecations under Sphinx 9
     'ignore:.*env\\.app.*:DeprecationWarning:myst_parser',
     # Windows issues, some may need to be fixed in MyST-NB, others are upstream
diff --git a/tox.ini b/tox.ini
index 42d442e8..f276f897 100644
--- a/tox.ini
+++ b/tox.ini
@@ -16,7 +16,7 @@ envlist = py313-sphinx8
 [testenv]
 usedevelop = true
 
-[testenv:py{310,311,312,313}-sphinx{5,6,7,8}]
+[testenv:py{310,311,312,313,314}-sphinx{5,6,7,8}]
 extras = testing
 deps =
     sphinx5: sphinx>=5,<6