diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index b02f15ea6..883570d54 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -56,14 +56,13 @@ jobs:
           [ -z "$ERROR" ] || exit 1
 
       - name: Setup Python
-        uses: actions/setup-python@v3
+        uses: actions/setup-python@v4
         with:
           python-version: 3.8
+          cache: 'pip' # uses requirements.txt
 
       - name: Install Python dependencies
-        run: |
-          pip install --upgrade pip
-          pip install .[ci]
+        run: pip install -r requirements.txt
 
       - name: "Run MyPy Type Checker - DiscoPoP Explorer"
         run: python -m mypy -p discopop_explorer
diff --git a/discopop_explorer/__main__.py b/discopop_explorer/__main__.py
index 6a6e020ef..acb194fe6 100644
--- a/discopop_explorer/__main__.py
+++ b/discopop_explorer/__main__.py
@@ -82,6 +82,8 @@
     }
 )
 
+# does the caching work?
+
 
 def get_path(base_path: str, file_name: str) -> str:
     """Combines path and filename if it is not absolute
diff --git a/requirements.txt b/requirements.txt
index 9fb63cf2b..1492ea509 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,19 +3,22 @@
 # Copyright (c) 2020, Technische Universitaet Darmstadt, Germany
 #
 # This software may be modified and distributed under the terms of
-# the 3-Clause BSD License. See the LICENSE file in the package base
+# the 3-Clause BSD License.  See the LICENSE file in the package base
 # directory for details.
 
---index-url https://pypi.python.org/simple/
-
+about-time==4.2.1
+alive-progress==3.1.4
 appdirs==1.4.4
+black==23.7.0
+click==8.1.7
 contextlib2==21.6.0
 contourpy==1.1.0
 cycler==0.11.0
-discopop @ file:///home/bg/dp-workspace/discopop
+data-science-types==0.2.23
 docopt==0.6.2
-extrap==4.1.0
+extrap==4.0.3
 fonttools==4.42.1
+grapheme==0.6.0
 importlib-resources==6.0.1
 jsonpickle==3.0.2
 jsons==1.6.3
@@ -25,26 +28,30 @@ marshmallow==3.20.1
 matplotlib==3.7.2
 mergedeep==1.3.4
 mpmath==1.3.0
+mypy==1.5.1
+mypy-extensions==1.0.0
 networkx==3.1
 numpy==1.24.4
-packaging==20.9
+packaging==23.1
+pathspec==0.11.2
 Pillow==10.0.0
-pkg_resources==0.0.0
+pip==23.2.1
+platformdirs==3.10.0
 pluginbase==1.0.1
 pstats2==0.1.0
 pycubexr==1.2.1
 pyparsing==3.0.9
-PySide6==6.5.2
-PySide6-Addons==6.5.2
-PySide6-Essentials==6.5.2
+PySide2==5.15.2.1
 python-dateutil==2.8.2
 recordtype==1.4
 schema==0.7.5
-shiboken6==6.5.2
+setuptools==44.0.0
+shiboken2==5.15.2.1
 six==1.16.0
 sympy==1.12
 sympy-plot-backends==2.4.3
+tomli==2.0.1
 tqdm==4.66.1
+typing_extensions==4.7.1
 typish==1.9.3
 zipp==3.16.2
-alive_progress==3.1.4