diff --git a/nkn-sdk-net/Ncp/Ncp.csproj b/nkn-sdk-net/Ncp/Ncp.csproj
index f193631..1669d1a 100644
--- a/nkn-sdk-net/Ncp/Ncp.csproj
+++ b/nkn-sdk-net/Ncp/Ncp.csproj
@@ -5,7 +5,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Google.Protobuf" Version="3.11.4" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.0" />
     <PackageReference Include="Open.ChannelExtensions" Version="3.4.0" />
     <PackageReference Include="protobuf-net" Version="2.4.6" />
     <PackageReference Include="System.Linq.Async" Version="4.1.1" />
diff --git a/nkn-sdk-net/NknSdk/NknSdk.csproj b/nkn-sdk-net/NknSdk/NknSdk.csproj
index 241778e..460771e 100644
--- a/nkn-sdk-net/NknSdk/NknSdk.csproj
+++ b/nkn-sdk-net/NknSdk/NknSdk.csproj
@@ -7,7 +7,7 @@
   <ItemGroup>
     <PackageReference Include="Base58Check" Version="0.2.0" />
     <PackageReference Include="dlech.Chaos.NaCl" Version="0.1.0" />
-    <PackageReference Include="Google.Protobuf" Version="3.11.4" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.0" />
     <PackageReference Include="HashLib" Version="2.0.1" />
     <PackageReference Include="Microsoft.Extensions.Caching.Memory" Version="3.1.3" />
     <PackageReference Include="Microsoft.Extensions.Options" Version="3.1.3" />