diff --git a/.test/23c/spack-environments b/.test/23c/spack-environments
new file mode 160000
index 0000000000000000000000000000000000000000..4429e6640f2d1460dd5ea88c517dea484825afd0
--- /dev/null
+++ b/.test/23c/spack-environments
@@ -0,0 +1 @@
+Subproject commit 4429e6640f2d1460dd5ea88c517dea484825afd0
diff --git a/pyproject.toml b/pyproject.toml
index 1be96ea8aa4338936a0394438542f159e95181b4..314a0a6bf2aa12dde6415e16e4d60425c47f2a99 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -7,7 +7,7 @@ name = "mpsd_software_manager"
 authors = [{name = "SSU-Computational Science (Fangohr et al)", email = "ssu-cs@mpsd.mpg.de"}]
 license = {file = "LICENSE"}
 classifiers = ["License :: OSI Approved :: MIT License"]
-version = "2023.12.12"
+version = "2023.12.18"
 readme = "README.rst"
 requires-python = ">=3.9"
 dependencies = [
diff --git a/src/mpsd_software_manager/cmds/install.py b/src/mpsd_software_manager/cmds/install.py
index 5dc588d57c41f9ca8ee35da6aa6369fe147a8985..9ff6c09006603fd76d4ab6d6b313a4c261081f29 100644
--- a/src/mpsd_software_manager/cmds/install.py
+++ b/src/mpsd_software_manager/cmds/install.py
@@ -64,9 +64,10 @@ def install_environment(
     # run the prepare_environment function
     available_package_sets = prepare_environment(mpsd_release, root_dir)
     # Ensure that the requested package_sets are available in the release
-    if package_sets == "ALL":
+    if package_sets == ["ALL"]:
         package_sets = available_package_sets
     elif package_sets == "NONE":
+        # TODO: This if case is never reached, because of new argparse logic. Remove it.
         # No package_sets requested, so we only create the env and print the
         # list of available package_sets
         logging.warning(