diff --git a/requirements.txt b/requirements.txt
index d04801a..f31a460 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -41,7 +41,7 @@ pexpect==4.4.0
 pickleshare==0.7.4
 Pillow==5.0.0
 prompt-toolkit==1.0.15
-protobuf==3.5.1
+protobuf==3.15.0
 ptyprocess==0.5.2
 pydot==1.2.3
 Pygments==2.2.0