diff --git a/explainer/requirements.txt b/explainer/requirements.txt
index 87a0f3e..62056be 100644
--- a/explainer/requirements.txt
+++ b/explainer/requirements.txt
@@ -51,7 +51,7 @@ pexpect==4.7.0
 pickleshare==0.7.5
 prometheus-client==0.7.1
 prompt-toolkit==2.0.9
-protobuf==3.9.0
+protobuf==3.18.3
 ptyprocess==0.6.0
 pycodestyle==2.5.0
 pyflakes==2.1.1