diff --git a/requirements.txt b/requirements.txt
index 8c98f32..953e810 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,7 +1,7 @@
 cycler==0.10.0
 kiwisolver==1.1.0
 matplotlib==3.1.1
-nltk==3.4.5
+nltk==3.6.6
 numpy==1.16.4
 pandas==0.24.2
 Pillow==8.1.1