diff --git a/requirements.txt b/requirements.txt
index 74a256f..ae81953 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -12,7 +12,7 @@ Jinja2==3.1.2
 jsonrpclib-pelix==0.3.1
 MarkupSafe==2.1.1
 mpmath==1.0.0
-nltk==3.7
+nltk==3.9.4
 -e git+https://github.com/ag-gipp/PPP-datamodel-Python.git@0c7958fb4df75468fd3137240a5065925c239776#egg=ppp_datamodel
 -e git+https://github.com/ag-gipp/PPP-libmodule-Python.git@8098ec3e3ac62f471ff93fb8ce29e36833a8d492#egg=ppp_libmodule
 -e git+https://github.com/ag-gipp/PPP-QuestionParsing-Grammatical.git@4c488f1bf57a0a4e29131a8e7a65ff94f192a5f5#egg=ppp_questionparsing_grammatical