diff --git a/requirements.txt b/requirements.txt
index d4dc1f7..3f251dc 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -22,7 +22,7 @@ matplotlib==3.1.1
 mccabe==0.6.1
 numpy==1.17.2
 oauth2client==3.0.0
-protobuf==3.10.0rc1
+protobuf==3.15.0
 pyasn1==0.4.7
 pyasn1-modules==0.2.6
 pycodestyle==2.5.0