diff --git a/capsnet-arch/requirements.txt b/capsnet-arch/requirements.txt
index 8da22e5..5d758ae 100644
--- a/capsnet-arch/requirements.txt
+++ b/capsnet-arch/requirements.txt
@@ -54,7 +54,7 @@ pexpect==4.8.0
 pickleshare==0.7.5
 prometheus-client==0.7.1
 prompt-toolkit==2.0.9
-protobuf==3.8.0
+protobuf==3.18.3
 ptyprocess==0.6.0
 Pygments==2.4.2
 pyparsing==2.4.0