diff --git a/requirements.txt b/requirements.txt
old mode 100755
new mode 100644
index 8e850f9..355757b
--- a/requirements.txt
+++ b/requirements.txt
@@ -15,7 +15,7 @@ jupyter-console==5.1.0
 jupyter-core==4.3.0
 MarkupSafe==1.0
 matplotlib==2.0.0
-nbconvert==5.1.1
+nbconvert==6.3.0
 nbformat==4.3.0
 numpy==1.12.1
 packaging==16.8