diff --git a/.ci_support/environment-mini.yml b/.ci_support/environment-mini.yml
index f2194ddf..26e53abb 100644
--- a/.ci_support/environment-mini.yml
+++ b/.ci_support/environment-mini.yml
@@ -5,3 +5,4 @@ dependencies:
 - numpy
 - cloudpickle =3.1.0
 - pyzmq =26.0.3
+- setuptools =75.1.0
diff --git a/.ci_support/environment-mpich.yml b/.ci_support/environment-mpich.yml
index 411ecde6..0eaa4e3f 100644
--- a/.ci_support/environment-mpich.yml
+++ b/.ci_support/environment-mpich.yml
@@ -13,3 +13,4 @@ dependencies:
 - pygraphviz =1.14
 - ipython =8.29.0
 - pysqa =0.2.0
+- setuptools =75.1.0
diff --git a/.ci_support/environment-openmpi.yml b/.ci_support/environment-openmpi.yml
index b2d7c810..c682edb4 100644
--- a/.ci_support/environment-openmpi.yml
+++ b/.ci_support/environment-openmpi.yml
@@ -13,3 +13,4 @@ dependencies:
 - pygraphviz =1.14
 - pysqa =0.2.0
 - ipython =8.29.0
+- setuptools =75.1.0
diff --git a/.ci_support/environment-win.yml b/.ci_support/environment-win.yml
index edae76c8..142bb419 100644
--- a/.ci_support/environment-win.yml
+++ b/.ci_support/environment-win.yml
@@ -12,3 +12,4 @@ dependencies:
 - networkx =3.4.2
 - pygraphviz =1.14
 - ipython =8.29.0
+- setuptools =75.1.0
diff --git a/.github/workflows/unittest-mpich.yml b/.github/workflows/unittest-mpich.yml
index 5c12f105..99b0e603 100644
--- a/.github/workflows/unittest-mpich.yml
+++ b/.github/workflows/unittest-mpich.yml
@@ -15,7 +15,10 @@ jobs:
       matrix:
         include:
         - operating-system: macos-latest
-          python-version: '3.12'
+          python-version: '3.13'
+
+        - operating-system: ubuntu-latest
+          python-version: '3.13'
 
         - operating-system: ubuntu-latest
           python-version: '3.12'
diff --git a/.github/workflows/unittest-openmpi.yml b/.github/workflows/unittest-openmpi.yml
index 69f09961..0c9b77c0 100644
--- a/.github/workflows/unittest-openmpi.yml
+++ b/.github/workflows/unittest-openmpi.yml
@@ -15,7 +15,10 @@ jobs:
       matrix:
         include:
         - operating-system: macos-latest
-          python-version: '3.12'
+          python-version: '3.13'
+          
+        - operating-system: ubuntu-latest
+          python-version: '3.13'
           
         - operating-system: ubuntu-latest
           python-version: '3.12'
diff --git a/.github/workflows/unittest-win.yml b/.github/workflows/unittest-win.yml
index 91186e43..76b7ec6c 100644
--- a/.github/workflows/unittest-win.yml
+++ b/.github/workflows/unittest-win.yml
@@ -14,7 +14,7 @@ jobs:
     strategy:
       matrix:
         operating-system: [windows-latest]
-        python-version: ['3.12']
+        python-version: ['3.13']
 
     steps:
     - uses: actions/checkout@v4
diff --git a/pyproject.toml b/pyproject.toml
index 5a0563c6..2ae84e1a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,7 +11,7 @@ authors = [
 readme = "README.md"
 license = { file = "LICENSE" }
 keywords = ["pyiron"]
-requires-python = ">=3.9, <3.13"
+requires-python = ">=3.9, <3.14"
 classifiers = [
     "Development Status :: 5 - Production/Stable",
     "Topic :: Scientific/Engineering :: Physics",
@@ -22,6 +22,7 @@ classifiers = [
     "Programming Language :: Python :: 3.10",
     "Programming Language :: Python :: 3.11",
     "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
 ]
 dependencies = [
     "cloudpickle==3.1.0",