diff --git a/requirements.txt b/requirements.txt
old mode 100755
new mode 100644
index df82c2f..bb1c53f
--- a/requirements.txt
+++ b/requirements.txt
@@ -55,7 +55,7 @@ msgpack-numpy==0.4.1
 msgpack-python==0.5.4
 multidict==4.3.1
 murmurhash==0.28.0
-nbconvert==5.3.1
+nbconvert==6.5.1
 nbformat==4.4.0
 networkx==2.1
 nltk==3.2.5