diff --git a/requirements_opacity_api.txt b/requirements_opacity_api.txt
index 4563853..b74a882 100644
--- a/requirements_opacity_api.txt
+++ b/requirements_opacity_api.txt
@@ -29,7 +29,7 @@ lru-dict==1.1.6
 multiaddr==0.0.9
 netaddr==0.7.19
 parsimonious==0.8.1
-protobuf==3.11.3
+protobuf==3.18.3
 pyaes==1.6.1
 pycparser==2.20
 pycryptodome==3.9.7