diff --git a/books/zero_to_deep_learning/requirements.txt b/books/zero_to_deep_learning/requirements.txt
old mode 100755
new mode 100644
index b5ad23a..f835b59
--- a/books/zero_to_deep_learning/requirements.txt
+++ b/books/zero_to_deep_learning/requirements.txt
@@ -39,7 +39,7 @@ mistune==0.8.3
 more-itertools==4.2.0
 nbconvert==5.3.1
 nbformat==4.4.0
-notebook==5.7.8
+notebook==6.4.12
 numpy==1.14.5
 pandas==0.23.3
 pandocfilters==1.4.2