diff --git a/requirements_cpu.txt b/requirements_cpu.txt
index c40395f..fd7c8c2 100644
--- a/requirements_cpu.txt
+++ b/requirements_cpu.txt
@@ -21,7 +21,7 @@ numpy==1.15.4
 opencv-python==3.4.3.18
 pbr==5.1.1
 Pillow==5.3.0
-protobuf==3.6.1
+protobuf==3.18.3
 pyparsing==2.3.0
 python-dateutil==2.7.5
 pytz==2018.7