diff --git a/pyproject.toml b/pyproject.toml
index 750fa7af..5dc4009a 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -20,6 +20,7 @@ matplotlib-inline = "^0.1.6"
 eindex = {git = "https://github.com/callummcdougall/eindex.git"}
 datasets = "^2.17.1"
 babe = "^0.0.7"
+nltk = "^3.8.1"
 
 
 [tool.poetry.group.dev.dependencies]