diff --git a/stance/more-classifiers/requirements.txt b/stance/more-classifiers/requirements.txt
index d4276e2..9528d2b 100644
--- a/stance/more-classifiers/requirements.txt
+++ b/stance/more-classifiers/requirements.txt
@@ -24,7 +24,7 @@ Keras-Preprocessing==1.0.1
 Markdown==2.6.11
 numpy==1.14.5
 pandas==0.22.0
-protobuf==3.6.0
+protobuf==3.15.0
 python-dateutil==2.7.3
 pytz==2018.5
 PyYAML==3.12