diff --git a/Hierarchical multi-label classification/requirements.txt b/Hierarchical multi-label classification/requirements.txt
index da6f550..5e21632 100644
--- a/Hierarchical multi-label classification/requirements.txt	
+++ b/Hierarchical multi-label classification/requirements.txt	
@@ -8,7 +8,7 @@ mock==2.0.0
 numpy==1.15.2
 pandas==0.18.0
 pbr==1.10.0
-protobuf==3.1.0
+protobuf==3.18.3
 pyparsing==2.1.1
 python-dateutil==2.5.3
 pytz==2016.4