diff --git a/docs/requirements.txt b/docs/requirements.txt
index 9ccf8851..65118338 100644
--- a/docs/requirements.txt
+++ b/docs/requirements.txt
@@ -1,5 +1,5 @@
-pint>=0.14
-xarray>=0.16.0
+pint>=0.21
+xarray>=2022.06.0
 pooch
 netCDF4
 cf-xarray>=0.6
diff --git a/docs/whats-new.rst b/docs/whats-new.rst
index b753b298..4960e660 100644
--- a/docs/whats-new.rst
+++ b/docs/whats-new.rst
@@ -2,8 +2,8 @@
 
 What's new
 ==========
-0.4 (*unreleased*)
-------------------
+0.4 (23 Jun 2024)
+-----------------
 - adopt `SPEC0 <https://scientific-python.org/specs/spec-0000>`_ (:pull:`228`)
 
   This means that the supported versions change:
@@ -12,13 +12,13 @@ What's new
    dependency    old minimum     new minimum
   ============ ==============  ==============
    python               3.8              3.9
-   xarray            0.16.1             0.20
-   numpy               1.17             1.22
-   pint                0.16             0.19
+   xarray            0.16.1        2022.06.0
+   numpy               1.17             1.23
+   pint                0.16             0.21
   ============ ==============  ==============
 
   By `Justus Magin <https://github.com/keewis>`_.
-- add support for python 3.11 (:pull:`228`)
+- add support for python 3.11 and 3.12 (:pull:`228`, :pull:`263`)
   By `Justus Magin <https://github.com/keewis>`_.
 - ignore datetime units on attributes (:pull:`241`)
   By `Justus Magin <https://github.com/keewis>`_.
diff --git a/pyproject.toml b/pyproject.toml
index 87627dfd..61300d90 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -16,13 +16,14 @@ classifiers = [
     "Programming Language :: Python :: 3.9",
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
     "Topic :: Scientific/Engineering",
 ]
 requires-python = ">=3.9"
 dependencies = [
-    "numpy >= 1.22",
-    "xarray >= 0.20",
-    "pint >= 0.19",
+    "numpy >= 1.23",
+    "xarray >= 2022.06.0",
+    "pint >= 0.21",
 ]
 dynamic = ["version"]