diff --git a/requirements.txt b/requirements.txt
index b306926..3ddac34 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -38,7 +38,7 @@ numpy==1.14.2
 packaging==17.1
 pathlib2==2.3.2
 poyo==0.4.1
-protobuf==3.5.2.post1
+protobuf==3.15.0
 pyasn1==0.4.2
 pycodestyle==2.3.1
 pyflakes==1.6.0