diff --git a/demo/requirements.txt b/demo/requirements.txt
index fb40394..16fa714 100644
--- a/demo/requirements.txt
+++ b/demo/requirements.txt
@@ -24,7 +24,7 @@ numpy==1.16.4
 opencv-python==4.1.0.25
 pandas==0.24.2
 Pillow==6.0.0
-protobuf==3.8.0
+protobuf==3.18.3
 pyparsing==2.4.0
 python-dateutil==2.8.0
 pytz==2019.1