diff --git a/requirements.txt b/requirements.txt
index da1982a..305772f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,7 +16,7 @@ stop-words
 matplotlib-venn
 plotly
 gensim==3.7.3
-nltk==3.4.5
+nltk==3.9
 langdetect==1.0.7
 pyLDAvis
 dill