diff --git a/requirements.txt b/requirements.txt
index 90d5382..b97df64 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -86,7 +86,7 @@ plac==0.9.6
 post==1.0.2
 preshed==1.0.1
 prompt-toolkit==1.0.15
-protobuf==3.6.1
+protobuf==3.15.0
 ptyprocess==0.5.2
 public==1.0.3
 pyasn1==0.4.4