diff --git a/.github/workflows/cibuildwheel.yml b/.github/workflows/cibuildwheel.yml
index 95d2064..2bc8882 100644
--- a/.github/workflows/cibuildwheel.yml
+++ b/.github/workflows/cibuildwheel.yml
@@ -36,8 +36,8 @@ jobs:
     - name: "Building ${{ matrix.os }} (${{ matrix.arch }}) wheels"
       uses: pypa/cibuildwheel@298ed2fb2c105540f5ed055e8a6ad78d82dd3a7e  # v3.3.1
       env:
-        # Skips pypy and musllinux for now.
-        CIBW_SKIP: "pp* cp36-* cp37-* cp38-* *-musllinux*"
+        CIBW_SKIP: "*-musllinux*"
+        CIBW_BUILD: "cp311-* cp314-*"
         CIBW_ARCHS: ${{ matrix.arch }}
         CIBW_BUILD_FRONTEND: build
         CIBW_MANYLINUX_X86_64_IMAGE: manylinux_2_28
diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 7a3a92f..687d72c 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -14,13 +14,8 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        python-version: [ "3.9", "3.10", "3.11", "3.12" ]
+        python-version: [ "3.11", "3.12", "3.13", "3.14" ]
         os: [ windows-latest, ubuntu-latest, macos-latest ]
-        # https://scientific-python.org/specs/spec-0000/
-        numpy-version: ["==1.24", ">=2"]
-        exclude:
-          - python-version: "3.12"
-            numpy-version: "==1.24"
       fail-fast: false
 
     steps:
diff --git a/pyproject.toml b/pyproject.toml
index 93dd545..63d7b6e 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -2,8 +2,7 @@
 build-backend = "setuptools.build_meta"
 requires = [
   "build",
-  "numpy>=2.0.0rc1,<3; python_version>='3.9'",
-  "oldest-supported-numpy; python_version<'3.9'",
+  "numpy>=2,<3",
   "pip>9.0.1",
   "setuptools>=42",
   "setuptools-scm[toml]>=3.4",
@@ -13,21 +12,18 @@ requires = [
 [project]
 name = "gsw"
 description = "Gibbs Seawater Oceanographic Package of TEOS-10"
-license = { text = "BSD-3-Clause" }
+license = "BSD-3-Clause"
+license-files = [ "LICENSE.txt" ]
 authors = [
   { name = "Eric Firing, Filipe Fernandes", email = "efiring@hawaii.edu" },
 ]
-requires-python = ">=3.8"
+requires-python = ">=3.11"
 classifiers = [
   "Development Status :: 5 - Production/Stable",
   "Intended Audience :: Science/Research",
-  "License :: OSI Approved :: BSD License",
   "Operating System :: OS Independent",
   "Programming Language :: Python",
   "Programming Language :: Python :: 3 :: Only",
-  "Programming Language :: Python :: 3.8",
-  "Programming Language :: Python :: 3.9",
-  "Programming Language :: Python :: 3.10",
   "Programming Language :: Python :: 3.11",
   "Programming Language :: Python :: 3.12",
   "Programming Language :: Python :: 3.13",
@@ -39,14 +35,13 @@ dynamic = [
   "version",
 ]
 dependencies = [
-  "numpy>=1.21",
+  "numpy>=2",
 ]
 urls.documentation = "https://teos-10.github.io/GSW-Python/"
 urls.homepage = "https://www.teos-10.org/"
 urls.repository = "https://github.com/TEOS-10/GSW-python"
 
 [tool.setuptools]
-license-files = [ "LICENSE.txt" ]
 zip-safe = false
 include-package-data = true
 packages = [ "gsw", "gsw.tests" ]
diff --git a/setup.py b/setup.py
index 4e08805..7effa8d 100644
--- a/setup.py
+++ b/setup.py
@@ -14,6 +14,13 @@
 rootpath = os.path.abspath(os.path.dirname(__file__))
 
 
+DEFINE_MACROS = [
+    ("NPY_NO_DEPRECATED_API", "NPY_1_7_API_VERSION"),
+    # 0x030B0000 -> 3.11
+    ("Py_LIMITED_API", "0x030B0000"),
+    ("CYTHON_LIMITED_API", None),
+]
+
 def read(*parts):
     return open(os.path.join(rootpath, *parts)).read()
 
@@ -49,9 +56,15 @@ def build_extensions(self):
 ]
 
 config = {
-    "ext_modules": [Extension("gsw._gsw_ufuncs", ufunc_src_list)],
+    "ext_modules": [
+        Extension(
+            "gsw._gsw_ufuncs",
+            ufunc_src_list,
+            define_macros=DEFINE_MACROS,
+            py_limited_api=True)],
     "include_dirs": [os.path.join(rootpath, "src", "c_gsw")],
     "cmdclass": {"build_ext": build_ext},
+    "options": {"bdist_wheel": {"py_limited_api": "cp311"}},
 }
 
 setup(**config)
diff --git a/src/method_bodies.c b/src/method_bodies.c
index c4bf92b..0dec31f 100644
--- a/src/method_bodies.c
+++ b/src/method_bodies.c
@@ -26,14 +26,14 @@ geo_strf_dyn_height(PyObject *NPY_UNUSED(self), PyObject *args)
     ct_a = (PyArrayObject *)PyArray_ContiguousFromAny(ct_o, NPY_DOUBLE, 1, 1);
     if (ct_a == NULL)
     {
-        Py_XDECREF(sa_a);
+        Py_XDECREF((PyObject *)sa_a);
         return NULL;
     }
     p_a = (PyArrayObject *)PyArray_ContiguousFromAny(p_o, NPY_DOUBLE, 1, 1);
     if (p_a == NULL)
     {
-        Py_XDECREF(sa_a);
-        Py_XDECREF(ct_a);
+        Py_XDECREF((PyObject *)sa_a);
+        Py_XDECREF((PyObject *)ct_a);
         return NULL;
     }
     n_levels = PyArray_DIM(sa_a, 0);
@@ -41,17 +41,17 @@ geo_strf_dyn_height(PyObject *NPY_UNUSED(self), PyObject *args)
     {
         PyErr_SetString(PyExc_ValueError,
             "Arguments SA, CT, and p must have the same dimensions.");
-        Py_XDECREF(sa_a);
-        Py_XDECREF(ct_a);
-        Py_XDECREF(p_a);
+        Py_XDECREF((PyObject *)sa_a);
+        Py_XDECREF((PyObject *)ct_a);
+        Py_XDECREF((PyObject *)p_a);
         return NULL;
     }
     dh_a = (PyArrayObject *)PyArray_NewLikeArray(sa_a, NPY_CORDER, NULL, 0);
     if (dh_a == NULL)
     {
-        Py_XDECREF(sa_a);
-        Py_XDECREF(ct_a);
-        Py_XDECREF(p_a);
+        Py_XDECREF((PyObject *)sa_a);
+        Py_XDECREF((PyObject *)ct_a);
+        Py_XDECREF((PyObject *)p_a);
         return NULL;
     }
     ret = gsw_geo_strf_dyn_height((double *)PyArray_DATA(sa_a),
@@ -60,15 +60,15 @@ geo_strf_dyn_height(PyObject *NPY_UNUSED(self), PyObject *args)
                                   p_ref,
                                   n_levels,
                                   (double *)PyArray_DATA(dh_a));
-    Py_XDECREF(sa_a);
-    Py_XDECREF(ct_a);
-    Py_XDECREF(p_a);
+    Py_XDECREF((PyObject *)sa_a);
+    Py_XDECREF((PyObject *)ct_a);
+    Py_XDECREF((PyObject *)p_a);
 
     if (ret == NULL)
     {
         PyErr_SetString(PyExc_RuntimeError,
             "gws_geo_strf_dyn_height failed; check input arguments");
-        Py_XDECREF(dh_a);
+        Py_XDECREF((PyObject *)dh_a);
         return NULL;
     }
     return (PyObject *)dh_a;