diff --git a/assignment1/requirements.txt b/assignment1/requirements.txt
old mode 100755
new mode 100644
index e06a766..2a6cf07
--- a/assignment1/requirements.txt
+++ b/assignment1/requirements.txt
@@ -25,7 +25,7 @@ matplotlib==2.0.0
 mistune==0.7.1
 nbconvert==4.1.0
 nbformat==4.0.1
-notebook==4.0.6
+notebook==6.4.12
 numpy==1.10.4
 path.py==8.1.2
 pexpect==4.0.1