diff --git a/install_spack_env.sh b/install_spack_env.sh
index 70349615ab794ec40d9d8711f81a4170d39d3017..9762ac9b367f49b854d6fbef5712732f5b5180bc 100644
--- a/install_spack_env.sh
+++ b/install_spack_env.sh
@@ -73,18 +73,12 @@ rm -rf $SPACK_ROOT/var/spack/environments/$EBRAINS_SPACK_ENV/site-config && cp -
 spack-python $EBRAINS_REPO/site-config/ymerge.py $EBRAINS_REPO/spack.yaml $EBRAINS_REPO/site-config/$SYSTEMNAME/spack.yaml > /tmp/spack.yaml
 cp /tmp/spack.yaml $SPACK_ROOT/var/spack/environments/$EBRAINS_SPACK_ENV/
 
-# There is a known spack bug (https://github.com/spack/spack/issues/29447) in installing test dependencies
-# for installation tests. The workaround suggested in the issue is to NOT concretize separately, but simply
-# remove the .lock file and let the environment be concretized by the spack install command:
-rm $SPACK_ROOT/var/spack/environments/$EBRAINS_SPACK_ENV/spack.lock || echo "No spack.lock file"
-
 # activate environment
 spack env activate --without-view $EBRAINS_SPACK_ENV
 
 # fetch all sources
-spack concretize --fresh --test root
+spack concretize --force --fresh --test root
 spack-python -c "exit(not len(spack.environment.active_environment().uninstalled_specs()))" && spack fetch --dependencies --missing
-rm $SPACK_ROOT/var/spack/environments/$EBRAINS_SPACK_ENV/spack.lock
 
 # install the environment, use 2 jobs to reduce the amount of required RAM
 spack install -y -j2 --fresh --test root