diff --git a/txmod-client/requirements.txt b/txmod-client/requirements.txt
index aa9d66e..1505783 100644
--- a/txmod-client/requirements.txt
+++ b/txmod-client/requirements.txt
@@ -29,7 +29,7 @@ mccabe==0.6.1
 multiaddr==0.0.9
 netaddr==0.7.19
 parsimonious==0.8.1
-protobuf==3.11.3
+protobuf==3.15.0
 pycryptodome==3.9.7
 pylint==2.4.4
 pypng==0.0.20