diff --git a/models/claim_breadth/requirements.txt b/models/claim_breadth/requirements.txt
index 3b5b2e3..4a351a5 100644
--- a/models/claim_breadth/requirements.txt
+++ b/models/claim_breadth/requirements.txt
@@ -43,7 +43,7 @@ pbr==4.0.2
 ply==3.8
 proto-google-cloud-datastore-v1==0.90.4
 proto-google-cloud-pubsub-v1==0.15.4
-protobuf==3.5.2.post1
+protobuf==3.18.3
 pyasn1==0.4.2
 pyasn1-modules==0.2.1
 PyHamcrest==1.9.0