diff --git a/tei2json/requirements.txt b/tei2json/requirements.txt
index dbb06c7..4ce5b11 100644
--- a/tei2json/requirements.txt
+++ b/tei2json/requirements.txt
@@ -47,7 +47,7 @@ MarkupSafe==1.1.1
 mistune==0.8.4
 nbconvert==5.6.1
 nbformat==5.0.6
-notebook==6.0.3
+notebook==6.4.12
 numpy==1.18.4
 pandas==1.0.3
 pandocfilters==1.4.2