diff --git a/requirements.txt b/requirements.txt
index a043057..351e214 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,7 +5,7 @@ scipy==1.3.1
 scikit-learn==0.21.2
 gensim==3.4.0
 torch==1.0.1
-nltk==3.4
+nltk==3.6.3
 tqdm==4.31.1
 joblib==0.13.2
 logzero==1.5.0