diff --git a/.github/workflows/run_unit_tests.yml b/.github/workflows/run_unit_tests.yml
index a5f084b..d1ec05b 100644
--- a/.github/workflows/run_unit_tests.yml
+++ b/.github/workflows/run_unit_tests.yml
@@ -40,7 +40,7 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -r requirements.txt
-        pip install .[dev]
+        pip install -r dev-requirements.txt
     - name: List packages
       run:
         pip list
diff --git a/dev-requirements.txt b/dev-requirements.txt
new file mode 100644
index 0000000..f725d8a
--- /dev/null
+++ b/dev-requirements.txt
@@ -0,0 +1,8 @@
+ipykernel
+coverage[toml]
+sphinx
+recommonmark
+sphinx_rtd_theme
+sphinx-autoapi
+pylint
+black == 21.12b
diff --git a/pyproject.toml b/pyproject.toml
index a60bcee..444a423 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -23,18 +23,6 @@ dependencies = [
 [project.urls]
 Repository = "https://github.com/spine-tools/spine-engine"
 
-[project.optional-dependencies]
-dev = [
-    "ipykernel",
-    "coverage[toml]",
-    "sphinx",
-    "recommonmark",
-    "sphinx_rtd_theme",
-    "sphinx-autoapi",
-    "pylint",
-    "black == 21.12b0"
-]
-
 [build-system]
 requires = ["setuptools>=64", "setuptools_scm[toml]>=6.2", "wheel", "build"]
 build-backend = "setuptools.build_meta"
diff --git a/requirements.txt b/requirements.txt
index 8fc365f..d289940 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,2 +1,2 @@
--e git+https://github.com/spine-tools/Spine-Database-API.git@0.8-dev#egg=spinedb_api
+-e git+https://github.com/spine-tools/Spine-Database-API.git@toolbox_2522_enable_python_3.12#egg=spinedb_api
 -e .