diff --git a/Ch4/ch4-requirements.txt b/Ch4/ch4-requirements.txt
index ae20396..ad72d54 100644
--- a/Ch4/ch4-requirements.txt
+++ b/Ch4/ch4-requirements.txt
@@ -1,4 +1,4 @@
-numpy==1.19.5
+numpy==1.22.0
 pandas==1.1.5
 scikit-learn==0.23.2
 nltk==3.5