diff --git a/libsignal-metadata-dotnet/libsignal-metadata-dotnet.csproj b/libsignal-metadata-dotnet/libsignal-metadata-dotnet.csproj
index 6a0188c..62f49de 100644
--- a/libsignal-metadata-dotnet/libsignal-metadata-dotnet.csproj
+++ b/libsignal-metadata-dotnet/libsignal-metadata-dotnet.csproj
@@ -21,7 +21,7 @@
 
   <ItemGroup>
     <!-- Do not upgrade! 3.12.4 is the last version to not include System.Memory (Span) which does not work on Windows 10 Mobile. -->
-    <PackageReference Include="Google.Protobuf" Version="3.12.4" />
+    <PackageReference Include="Google.Protobuf" Version="3.15.0" />
     <PackageReference Include="Google.Protobuf.Tools" Version="3.12.4" />
     <PackageReference Include="libsignal-protocol-dotnet" Version="2.8.1" />
     <!-- Do not upgrade! 1.8.5 is the last version that supports .NETStandard 1.4 -->