diff --git a/requirements.txt b/requirements.txt
index 9921e151a9be5bdf83aefc2db08c61f95edd93bf..3112b38263ea37286ffafffa6afa190a4180bfa2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -24,6 +24,7 @@ karabo_data == 0.7.0
 lxml == 4.5.0
 metadata_client == 3.0.5
 nbconvert == 5.6.1
+nbformat == 5.0.7
 prettytable == 0.7.2
 pypandoc == 1.4
 python-dateutil == 2.8.1