diff --git a/assignment1/requirements.txt b/assignment1/requirements.txt
old mode 100755
new mode 100644
index e06a766..1aa32e6
--- a/assignment1/requirements.txt
+++ b/assignment1/requirements.txt
@@ -22,7 +22,7 @@ jupyter-client==4.1.1
 jupyter-console==4.0.3
 jupyter-core==4.0.6
 matplotlib==2.0.0
-mistune==0.7.1
+mistune==0.8.1
 nbconvert==4.1.0
 nbformat==4.0.1
 notebook==4.0.6