diff --git a/requirements.txt b/requirements.txt
index cd73599..4bc89b6 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -3,7 +3,7 @@ konlpy==0.5.1
 numpy==1.17.2
 pandas==0.25.1
 Pillow==6.1.0
-protobuf==3.9.2
+protobuf==3.18.3
 python-dateutil==2.8.0
 pytz==2019.2
 six==1.12.0