diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 9e1a50a5..f9038eef 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -50,6 +50,26 @@ jobs:
       - name: Run tests
         run: |
           pytest -n auto
+  # TODO(jakevdp): remove this job after NumPy 2.0 release
+  build-numpy-2-pre:
+    name: Python 3.12 with numpy 2.0 pre-release
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v3
+      with:
+        submodules: true
+    - name: Set up Python 3.12
+      uses: actions/setup-python@v4
+      with:
+        python-version: 3.12
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip install .[dev]
+        pip install -U --pre numpy
+    - name: Run tests
+      run: |
+        pytest -n auto
   build-nightly:
     name: Python 3.12 with nightly numpy
     runs-on: ubuntu-latest
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 2d825c4a..e7d5b102 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,11 @@ To release a new version (e.g. from `1.0.0` -> `2.0.0`):
 
 ## [Unreleased]
 
+## [0.4.0b1] - 2024-03-12
+
+* Updates `ml_dtypes` for compatibility with future NumPy 2.0 release.
+* Wheels for the release candidate are built against NumPy 2.0.0b1.
+
 ## [0.3.2] - 2024-01-03
 
 * Fixed spurious invalid value warnings when casting between floating point
@@ -57,6 +62,7 @@ To release a new version (e.g. from `1.0.0` -> `2.0.0`):
 * Initial release
 
 [Unreleased]: https://github.com/jax-ml/ml_dtypes/compare/v0.3.2...HEAD
+[0.4.0b1]: https://github.com/jax-ml/ml_dtypes/compare/v0.3.2...v0.4.0b1
 [0.3.2]: https://github.com/jax-ml/ml_dtypes/compare/v0.3.1...v0.3.2
 [0.3.1]: https://github.com/jax-ml/ml_dtypes/compare/v0.3.0...v0.3.1
 [0.3.0]: https://github.com/jax-ml/ml_dtypes/compare/v0.2.0...v0.3.0
diff --git a/ml_dtypes/__init__.py b/ml_dtypes/__init__.py
index 1df78fb1..a7bb867d 100644
--- a/ml_dtypes/__init__.py
+++ b/ml_dtypes/__init__.py
@@ -12,7 +12,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-__version__ = '0.3.2'  # Keep in sync with pyproject.toml:version
+__version__ = '0.4.0b1'  # Keep in sync with pyproject.toml:version
 __all__ = [
     '__version__',
     'bfloat16',
diff --git a/pyproject.toml b/pyproject.toml
index e1b71224..b5b87ded 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "ml_dtypes"
-version = "0.3.2"  # Keep in sync with ml_dtypes/__init__.py:__version__
+version = "0.4.0b1"  # Keep in sync with ml_dtypes/__init__.py:__version__
 description = ""
 readme = "README.md"
 requires-python = ">=3.9"
@@ -48,10 +48,8 @@ pyink-use-majority-quotes = true
 
 [build-system]
 requires = [
-    # Build with oldest supported numpy for each Python version.
-    "numpy~=1.21.2; python_version<'3.11'",
-    "numpy~=1.23.3; python_version>='3.11' and python_version<'3.12'",
-    "numpy~=1.26.0; python_version>='3.12'",
+    # TODO(jakevdp): update this to 2.0.0rc1 before final release
+    "numpy==2.0.0b1",
     "setuptools~=68.1.0",
 ]
 build-backend = "setuptools.build_meta"