diff --git a/ProtoBufSerialize/packages.config b/ProtoBufSerialize/packages.config
index d48cfa2..57ffd5a 100644
--- a/ProtoBufSerialize/packages.config
+++ b/ProtoBufSerialize/packages.config
@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <packages>
-  <package id="Google.Protobuf" version="3.5.1" targetFramework="net452" />
+  <package id="Google.Protobuf" version="3.15.0" targetFramework="net452" />
 </packages>
\ No newline at end of file