diff --git a/docker/requirements.txt b/docker/requirements.txt
index 663ee2f..bc62ac0 100644
--- a/docker/requirements.txt
+++ b/docker/requirements.txt
@@ -35,4 +35,4 @@ sklearn_crfsuite==0.3.6
 keras-applications==1.0.6
 keras-preprocessing==1.0.5
 elasticsearch==6.3.1
-nltk==3.3
+nltk==3.4.5