diff --git a/requirements.txt b/requirements.txt
index 1569082..79e564b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -19,7 +19,7 @@ jinja2==3.0.1; python_version >= "3.6"
 joblib==1.0.1; python_version >= "3.6"
 livereload==2.6.3; python_version >= "3.6"
 markupsafe==2.0.1; python_version >= "3.6"
-nltk==3.6.2; python_version >= "3.5"
+nltk==3.6.6; python_version >= "3.5"
 packaging==21.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
 platformdirs==2.3.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"
 pluggy==1.0.0; python_version >= "3.6" and python_full_version < "3.0.0" or python_full_version >= "3.5.0" and python_version >= "3.6"