diff --git a/.appveyor_support/environments/requirements_py36.txt b/.appveyor_support/environments/requirements_py36.txt
index 4953d79..0e01767 100644
--- a/.appveyor_support/environments/requirements_py36.txt
+++ b/.appveyor_support/environments/requirements_py36.txt
@@ -44,7 +44,7 @@ nbconvert==5.5.0
 nbformat==4.4.0
 networkx==2.3
 nose==1.3.7
-notebook==6.1.5
+notebook==6.4.12
 numpy==1.13.3
 opencv-python==4.1.0.25
 pandocfilters==1.4.2