diff --git a/requirements.txt b/requirements.txt
index 6619b98..881cd9b 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -8,7 +8,7 @@ Keras-Preprocessing==1.0.5
 Markdown==3.0.1
 numpy==1.15.4
 Pillow==5.3.0
-protobuf==3.6.1
+protobuf==3.18.3
 scikit-learn==0.20.1
 scipy==1.1.0
 six==1.12.0