diff --git a/.github/workflows/download_data.yml b/.github/workflows/download_data.yml
index f218a18..a1e192c 100644
--- a/.github/workflows/download_data.yml
+++ b/.github/workflows/download_data.yml
@@ -16,6 +16,8 @@ jobs:
       - uses: actions/checkout@v4
       - name: Set up Python
         uses: actions/setup-python@v5
+        with:
+          python-version: 3.11
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
diff --git a/bin/download_scopesim_data.sh b/bin/download_scopesim_data.sh
index d212c9a..9926b50 100755
--- a/bin/download_scopesim_data.sh
+++ b/bin/download_scopesim_data.sh
@@ -58,16 +58,33 @@ pip install poetry
 
 # Download and install all the packages. Has to be done from git, because the
 # releases do not (always) have the test files.
-# TODO: Add speXtra and Pickles?
+# All poetry files are updated with `poetry update` to ensure we test the latest
+# versions of our dependencies.
+
+# Pyckles must go first, because otherwise it uninstalls scipy (????). See
+# https://stackoverflow.com/questions/67085976/how-to-stop-poetry-from-uninstalling-packages
+git clone https://github.com/AstarVienna/Pyckles.git
+pushd Pyckles
+poetry install --with=test,docs
+poetry update --with=test,docs
+popd
+
+git clone https://github.com/AstarVienna/speXtra.git
+pushd speXtra
+poetry install --with=test,docs
+poetry update --with=test,docs
+popd
 
 git clone https://github.com/AstarVienna/ScopeSim.git
 pushd ScopeSim
 poetry install --with=test,dev,docs
+poetry update --with=test,dev,docs
 popd
 
 git clone https://github.com/AstarVienna/skycalc_ipy.git
 pushd skycalc_ipy
 poetry install --with=test,docs
+poetry update --with=test,docs
 popd
 
 git clone https://github.com/AstarVienna/AnisoCADO.git
@@ -79,6 +96,7 @@ popd
 git clone https://github.com/AstarVienna/ScopeSim_Templates.git
 pushd ScopeSim_Templates
 poetry install --with=test,dev,docs
+poetry update --with=test,dev,docs
 popd
 
 git clone https://github.com/AstarVienna/irdb.git
@@ -87,9 +105,32 @@ pushd irdb
 pip install -e ".[test]"
 popd
 
+# poetry update will upgrade only to the latest versions that are released.
+# The packages will therefore downgrade each other.
+# But ScopeSim_Data should use the latest version of all our projects
+# (to download the data they need, and to test whether they work together).
+# So the projects need to be installed again.
+# Note that it is not possible to only use pip, poetry is required to install
+# the dependency groups (that is, dev/test/docs). See
+# https://stackoverflow.com/questions/76118614/is-it-possible-to-install-poetry-groups-with-pip
+pip install -e Pyckles
+pip install -e speXtra
+pip install -e ScopeSim
+pip install -e ScopeSim_Templates
+pip install -e skycalc_ipy
+pip install -e AnisoCADO
+pip install -e irdb
 
 
 # Run the tests.
+pushd Pyckles
+python -m pytest
+popd
+
+pushd speXtra
+python -m pytest
+popd
+
 pushd skycalc_ipy
 python -m pytest
 popd