diff --git a/site-config/ebrainslab/spack.yaml b/site-config/ebrainslab/spack.yaml
index 5e2f936370d131492c7287699cbfe3714ca55340..2533621056e19d28234ff4cf3e40551e78daab22 100644
--- a/site-config/ebrainslab/spack.yaml
+++ b/site-config/ebrainslab/spack.yaml
@@ -7,7 +7,7 @@ spack:
     - py-notebook
     - r-irkernel
     # "collab"-specific constraint to match ("jupyterlab_widgets") in the base image
-    - py-ipywidgets
+    - py-ipywidgets@7.7.0
+    - py-jupyterlab-widgets@1.1.0
     # Collab utils
     - clb-nb-utils@0.1.0
-