diff --git a/.github/workflows/make_bundle.yml b/.github/workflows/make_bundle.yml
index 6598c8acb..2626c0f20 100644
--- a/.github/workflows/make_bundle.yml
+++ b/.github/workflows/make_bundle.yml
@@ -21,8 +21,11 @@ jobs:
       - name: "Set up Python"
         uses: actions/setup-python@v5
         with:
-          python-version: "3.11"
+          python-version: "3.12"
           cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            requirements.txt
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
@@ -37,7 +40,7 @@ jobs:
         run: |
           mkdir embedded-python
           cd embedded-python
-          curl -o python.zip https://www.python.org/ftp/python/3.11.9/python-3.11.9-embed-amd64.zip
+          curl -o python.zip https://www.python.org/ftp/python/3.12.3/python-3.12.3-embed-amd64.zip
           tar xf python.zip
           del python.zip
       - name: Build bundle
diff --git a/.github/workflows/test_runner.yml b/.github/workflows/test_runner.yml
index 5ca43dedb..0c8ae02d0 100644
--- a/.github/workflows/test_runner.yml
+++ b/.github/workflows/test_runner.yml
@@ -18,7 +18,7 @@ jobs:
     strategy:
       fail-fast: true
       matrix:
-        python-version: [3.8, 3.9, "3.10", 3.11]
+        python-version: [3.8, 3.9, "3.10", 3.11, 3.12]
         os: [windows-latest, ubuntu-22.04]
     steps:
     - uses: actions/checkout@v4
@@ -32,8 +32,9 @@ jobs:
         python-version: ${{ matrix.python-version }}
         cache: pip
         cache-dependency-path: |
-          requirements.txt
           pyproject.toml
+          requirements.txt
+          dev-requirements.txt
     - name: Display Python version
       run:
          python -c "import sys; print(sys.version)"
@@ -48,16 +49,10 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install -r requirements.txt
+        python -m pip install -r dev-requirements.txt
     - name: List packages
       run:
         python -m pip list
-    - name: Install python3 kernelspecs
-      run: |
-        python -m pip install ipykernel
-        python -m ipykernel install --user
-    - name: Install coverage
-      run:
-        python -m pip install coverage[toml]
     - name: Run tests
       run: |
         if [ "$RUNNER_OS" != "Windows" ]; then
@@ -75,7 +70,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        python-version: [3.8, 3.9, "3.10", 3.11]
+        python-version: [3.8, 3.9, "3.10", 3.11, 3.12]
         os: [windows-latest, ubuntu-22.04]
 #    needs: unit-tests
     steps:
@@ -86,8 +81,9 @@ jobs:
         python-version: ${{ matrix.python-version }}
         cache: pip
         cache-dependency-path: |
-          requirements.txt
           pyproject.toml
+          requirements.txt
+          dev-requirements.txt
     - name: Install additional packages for Linux
       if: runner.os == 'Linux'
       run: |
@@ -99,6 +95,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         python -m pip install -r requirements.txt
+        python -m pip install -r dev-requirements.txt
     - name: List packages
       run: 
         python -m pip list
diff --git a/dev-requirements.txt b/dev-requirements.txt
index 7e949b5b8..338df871c 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -1,12 +1,9 @@
-black == 24.4.2
-pre-commit == 2.0.1
-PyYAML >= 5.4
-pylint >= 2.3.0
-setuptools >=64
-setuptools_scm[toml] >= 6.2
-build
-wheel >=0.36.2
-twine >= 3.4.1
 coverage[toml]
+black == 21.12b0
+pre-commit == 2.0.1
+pylint
 pyperf
--r "docs/requirements.txt"
+sphinx
+sphinx_rtd_theme
+sphinx-autoapi
+recommonmark
diff --git a/docs/requirements.txt b/docs/requirements.txt
deleted file mode 100644
index a80a2762e..000000000
--- a/docs/requirements.txt
+++ /dev/null
@@ -1,8 +0,0 @@
-markupsafe < 2.1  # Jinja2<3.0 tries to import soft_unicode, which has been removed in markupsafe 2.1
-jinja2 < 3.0  # Dagster 0.12.8 requires Jinja2<3.0
-docutils < 0.17
-sphinx < 5.2
-sphinx_rtd_theme
-recommonmark
-astroid < 3.0  # sphinx-autoapi installs the latest astroid. We are not compatible with astroid v3.0
-sphinx-autoapi < 2.1  # 2.1 removed support for sphinx < 5.2.0
diff --git a/pyproject.toml b/pyproject.toml
index 28ddff26f..ec7ad6fe7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -11,12 +11,11 @@ classifiers = [
     "License :: OSI Approved :: GNU Lesser General Public License v3 (LGPLv3)",
     "Operating System :: OS Independent",
 ]
-requires-python = ">=3.8.1, <3.12"
+requires-python = ">=3.8.1"
 dependencies = [
-    "pyside6 >= 6.5.0, != 6.5.3, != 6.6.3",
+    "pyside6 >= 6.5.0, != 6.5.3, != 6.6.3, != 6.7.0",
     "jupyter-client >=6.0",
     "qtconsole >=5.1",
-    "sqlalchemy >=1.3",
     "spinedb_api>=0.31.1",
     "spine_engine>=0.24.0",
     "numpy >=1.20.2",
diff --git a/requirements.txt b/requirements.txt
index 0ff41d492..93ee2dc10 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,4 @@
--e git+https://github.com/spine-tools/Spine-Database-API.git#egg=spinedb_api
--e git+https://github.com/spine-tools/spine-engine.git#egg=spine_engine
--e git+https://github.com/spine-tools/spine-items.git#egg=spine_items
+-e git+https://github.com/spine-tools/Spine-Database-API.git@toolbox_2522_enable_python_3.12#egg=spinedb_api
+-e git+https://github.com/spine-tools/spine-engine.git@toolbox_2522_enable_python_3.12#egg=spine_engine
+-e git+https://github.com/spine-tools/spine-items.git@2522_enable_python_3.12#egg=spine_items
 -e .
diff --git a/spinetoolbox/ui/settings.py b/spinetoolbox/ui/settings.py
index ead0c2f83..1cc454478 100644
--- a/spinetoolbox/ui/settings.py
+++ b/spinetoolbox/ui/settings.py
@@ -14,7 +14,7 @@
 ################################################################################
 ## Form generated from reading UI file 'settings.ui'
 ##
-## Created by: Qt User Interface Compiler version 6.7.0
+## Created by: Qt User Interface Compiler version 6.6.3
 ##
 ## WARNING! All changes made in this file will be lost when recompiling UI file!
 ################################################################################
@@ -406,8 +406,8 @@ def setupUi(self, SettingsForm):
 
         self.line_3 = QFrame(self.groupBox_julia)
         self.line_3.setObjectName(u"line_3")
-        self.line_3.setFrameShape(QFrame.Shape.VLine)
-        self.line_3.setFrameShadow(QFrame.Shadow.Sunken)
+        self.line_3.setFrameShape(QFrame.VLine)
+        self.line_3.setFrameShadow(QFrame.Sunken)
 
         self.horizontalLayout_14.addWidget(self.line_3)
 
@@ -489,8 +489,8 @@ def setupUi(self, SettingsForm):
 
         self.line = QFrame(self.groupBox_julia)
         self.line.setObjectName(u"line")
-        self.line.setFrameShape(QFrame.Shape.HLine)
-        self.line.setFrameShadow(QFrame.Shadow.Sunken)
+        self.line.setFrameShape(QFrame.HLine)
+        self.line.setFrameShadow(QFrame.Sunken)
 
         self.verticalLayout_10.addWidget(self.line)
 
@@ -543,8 +543,8 @@ def setupUi(self, SettingsForm):
 
         self.line_2 = QFrame(self.groupBox_python)
         self.line_2.setObjectName(u"line_2")
-        self.line_2.setFrameShape(QFrame.Shape.VLine)
-        self.line_2.setFrameShadow(QFrame.Shadow.Sunken)
+        self.line_2.setFrameShape(QFrame.VLine)
+        self.line_2.setFrameShadow(QFrame.Sunken)
 
         self.horizontalLayout_5.addWidget(self.line_2)