diff --git a/requirements.txt b/requirements.txt
index 35d3f55..4dcb709 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,7 +16,7 @@ matplotlib==2.2.2
 music21==4.1.0
 numpy==1.14.2
 pandas==0.22.0
-protobuf==3.5.2.post1
+protobuf==3.18.3
 pyparsing==2.2.0
 python-dateutil==2.7.2
 pytz==2018.4