diff --git a/create_JupyterLab_kernel.sh b/create_JupyterLab_kernel.sh
index a4c21118a691792019eba43aff3c3dbca82cd96c..f819f00cb99088ab6aea68696c02aa357eb8cf40 100644
--- a/create_JupyterLab_kernel.sh
+++ b/create_JupyterLab_kernel.sh
@@ -21,6 +21,9 @@ spack repo add /srv/$INSTALLATION_ROOT/ebrains-spack-builds
 
 module use /srv/$INSTALLATION_ROOT/spack/share/spack/modules/linux-centos7-broadwell/
 source /srv/$INSTALLATION_ROOT/spack/var/spack/environments/$SPACKIFIED_ENV/loads
+# add also user's .local python3.8 packages to allow package installation at runtime
+# by the user using pip
+export PYTHONPATH=$PYTHONPATH:/opt/app-root/src/.local/lib/python3.8/site-packages
 
 # capture the env after spack activation
 cd /opt/app-root/src
diff --git a/spack.yaml b/spack.yaml
index d8c472e451edc5ff67371771f6ed40201a49fce6..aefab57a3497c3b7ca831453308a4fa568d9ebb9 100644
--- a/spack.yaml
+++ b/spack.yaml
@@ -15,7 +15,7 @@ spack:
     - py-seaborn %gcc@10.3.0
     - py-matplotlib %gcc@10.3.0
     # EBRAINS simulators
-    - nest@3.1 +python +gsl +mpi %gcc@10.3.0
+    - nest@3.0 +python +gsl +mpi %gcc@10.3.0
     - arbor +mpi ^python@3:3.9 %gcc@10.3.0
     - neuron +mpi %gcc@10.3.0
     - py-pynn@0.9.6 %gcc@10.3.0