diff --git a/assignment2/requirements.txt b/assignment2/requirements.txt
old mode 100755
new mode 100644
index 3e6c302..59b7957
--- a/assignment2/requirements.txt
+++ b/assignment2/requirements.txt
@@ -23,7 +23,7 @@ jupyter-console==4.0.3
 jupyter-core==4.0.6
 matplotlib==1.5.0
 mistune==0.7.1
-nbconvert==4.1.0
+nbconvert==6.5.1
 nbformat==4.0.1
 notebook==4.0.6
 numpy==1.10.4