diff --git a/books/thoughtful_ml/requirements.txt b/books/thoughtful_ml/requirements.txt
old mode 100755
new mode 100644
index 3d11e0a..d7f4656
--- a/books/thoughtful_ml/requirements.txt
+++ b/books/thoughtful_ml/requirements.txt
@@ -24,7 +24,7 @@ mistune==0.8.3
 nbconvert==5.4.0
 nbformat==4.4.0
 nose==1.3.7
-notebook==5.7.8
+notebook==6.4.12
 numpy==1.15.1
 pandas==0.23.4
 pandocfilters==1.4.2