diff --git a/docs/tools/requirements.txt b/docs/tools/requirements.txt
index 0e3e3c24b5f..228229ac30d 100644
--- a/docs/tools/requirements.txt
+++ b/docs/tools/requirements.txt
@@ -20,7 +20,7 @@ MarkupSafe==1.1.1
 mkdocs==1.1
 mkdocs-htmlproofer-plugin==0.0.3
 mkdocs-macros-plugin==0.4.6
-nltk==3.4.5
+nltk==3.5
 nose==1.3.7
 protobuf==3.11.3
 numpy==1.18.2