diff --git a/_config.yml b/_config.yml
index 436b6d4..1def3b4 100644
--- a/_config.yml
+++ b/_config.yml
@@ -45,6 +45,7 @@ sphinx:
     - sphinx_multitoc_numbering
   config:
     bibtex_reference_style: author_year
+    nb_execution_raise_on_error: true 
 
 # Information about where the book exists on the web
 repository: