diff --git a/Procfile b/Procfile
index a453546..8393cfc 100644
--- a/Procfile
+++ b/Procfile
@@ -1 +1 @@
-web: voila --port=$PORT --no-browser --Voila.config_file_paths=./ OPTIMADE-Client.ipynb
+web: jupyter trust OPTIMADE-Client.ipynb & voila --port=$PORT --no-browser --Voila.config_file_paths=./ OPTIMADE-Client.ipynb
diff --git a/runtime.txt b/runtime.txt
index ffc8603..795ee72 100644
--- a/runtime.txt
+++ b/runtime.txt
@@ -1 +1 @@
-python-3.7.10
+python-3.7.9