diff --git a/requirements.txt b/requirements.txt
old mode 100755
new mode 100644
index df82c2f..04793bc
--- a/requirements.txt
+++ b/requirements.txt
@@ -61,7 +61,7 @@ networkx==2.1
 nltk==3.2.5
 nose==1.3.7
 nose-timer==0.7.1
-notebook==5.4.1
+notebook==6.4.12
 notedown==1.5.1
 numpy==1.14.3
 pandas==0.23.3