diff --git a/first-neural-network/requirements.txt b/first-neural-network/requirements.txt
old mode 100755
new mode 100644
index aac831fd7b..35ba58e4b2
--- a/first-neural-network/requirements.txt
+++ b/first-neural-network/requirements.txt
@@ -18,7 +18,7 @@ jupyter-core==4.3.0
 MarkupSafe==1.0
 matplotlib==2.0.0
 mistune==0.7.4
-nbconvert==5.1.1
+nbconvert==6.3.0
 nbformat==4.3.0
 notebook==4.4.1
 numpy==1.12.1