diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index dd3ec227..eb7de4f2 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -23,7 +23,7 @@ jobs:
       with:
         python-version: ${{ matrix.python-version }}
     - name: Install Python dependencies
-      run: python -m pip install --prefer-binary cython>=0.28 ${{ matrix.numpy-version }} scipy matplotlib "pyopencl[pocl]>=2022.2.4"
+      run: python -m pip install --prefer-binary cython~=3.0 ${{ matrix.numpy-version }} scipy matplotlib "pyopencl[pocl]>=2022.2.4"
     - name: Install Raysect from pypi
       run: pip install raysect==0.8.1
     - name: Build cherab
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 86a64e3a..3f5bcca4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,7 @@ API changes:
 
 New:
 * Support Raysect 0.8
+* Cython version 3 is now required to build the package.
 * Add custom line shape support to BeamCXLine model. (#394)
 * Add PeriodicTransformXD and VectorPeriodicTransformXD functions to support the data simulated with periodic boundary conditions. (#387)
 * Add CylindricalTransform and VectorCylindricalTransform to transform functions from cylindrical to Cartesian coordinates. (#387)
diff --git a/pyproject.toml b/pyproject.toml
index a4eabed0..ea724622 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,3 +1,3 @@
 [build-system]
-requires = ["setuptools>=62.3", "oldest-supported-numpy", "cython>=0.28", "raysect==0.8.1"]
+requires = ["setuptools>=62.3", "oldest-supported-numpy", "cython~=3.0", "raysect==0.8.1"]
 build-backend="setuptools.build_meta"
diff --git a/requirements.txt b/requirements.txt
index 3e98c385..e070e4ce 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
-cython>=0.28
+cython~=3.0
 numpy>=1.14,<2.0
 scipy
 matplotlib
diff --git a/setup.py b/setup.py
index eb56a797..baab310b 100644
--- a/setup.py
+++ b/setup.py
@@ -33,8 +33,9 @@
 
 source_paths = ["cherab", "demos"]
 compilation_includes = [".", numpy.get_include()]
-compilation_args = ["-O3"]
+compilation_args = ["-O3", "-Wno-unreachable-code-fallthrough"]
 cython_directives = {"language_level": 3}
+macros = [("NPY_NO_DEPRECATED_API", "NPY_1_7_API_VERSION")]
 setup_path = path.dirname(path.abspath(__file__))
 num_processes = int(os.getenv("CHERAB_NCPU", "-1"))
 if num_processes == -1:
@@ -61,6 +62,7 @@
                         [pyx_file],
                         include_dirs=compilation_includes,
                         extra_compile_args=compilation_args,
+                        define_macros=macros,
                     ),
                 )
 
@@ -122,7 +124,7 @@
     ],
     extras_require={
         # Running ./dev/build_docs.sh runs setup.py, which requires cython.
-        "docs": ["cython", "sphinx", "sphinx-rtd-theme", "sphinx-tabs"],
+        "docs": ["cython~=3.0", "sphinx", "sphinx-rtd-theme", "sphinx-tabs"],
     },
     packages=find_packages(include=["cherab*"]),
     package_data={"": [