diff --git a/requirements.txt b/requirements.txt
index 530dfd5..d714395 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@ kiwisolver==1.1.0
 matplotlib==3.1.1
 numpy==1.17.0
 Pillow==6.2.0
-protobuf==3.9.1
+protobuf==3.18.3
 pyparsing==2.4.2
 python-dateutil==2.8.0
 six==1.12.0