diff --git a/Directory.Packages.props b/Directory.Packages.props
index 3dc8d454..8f148d7a 100644
--- a/Directory.Packages.props
+++ b/Directory.Packages.props
@@ -27,7 +27,7 @@
     <PackageVersion Include="Microsoft.VisualStudio.Threading.Only" Version="$(VisualStudioThreadingVersion)" />
     <PackageVersion Include="Microsoft.VisualStudio.Threading" Version="$(VisualStudioThreadingVersion)" />
     <PackageVersion Include="Microsoft.VisualStudio.Validation" Version="17.13.22" />
-    <PackageVersion Include="Nerdbank.MessagePack" Version="0.11.54-rc" />
+    <PackageVersion Include="Nerdbank.MessagePack" Version="0.12.4-rc" />
     <PackageVersion Include="Nerdbank.Streams" Version="2.13.16" />
     <PackageVersion Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageVersion Include="System.Collections.Immutable" Version="8.0.0" />
diff --git a/src/StreamJsonRpc/RpcTargetMetadata.cs b/src/StreamJsonRpc/RpcTargetMetadata.cs
index bce8e2c9..4c027ea3 100644
--- a/src/StreamJsonRpc/RpcTargetMetadata.cs
+++ b/src/StreamJsonRpc/RpcTargetMetadata.cs
@@ -495,7 +495,7 @@ private static IReadOnlyList<Type> GetMissingInterfacesFromSet([DynamicallyAcces
         return missing ?? [];
     }
 
-    private static MethodInfo GetMethodInfo(IMethodShape shape) => (MethodInfo)(shape.AttributeProvider ?? throw new ArgumentException(Resources.FormatAttributeProviderRequired($"{shape.DeclaringType.Type.FullName}.{shape.Name}"), nameof(shape)));
+    private static MethodInfo GetMethodInfo(IMethodShape shape) => (MethodInfo)(shape.MethodBase ?? throw new ArgumentException(Resources.FormatAttributeProviderRequired($"{shape.DeclaringType.Type.FullName}.{shape.Name}"), nameof(shape)));
 
     internal struct RpcTargetInterface([DynamicallyAccessedMembers(DynamicallyAccessedMemberTypes.PublicMethods | DynamicallyAccessedMemberTypes.NonPublicMethods | DynamicallyAccessedMemberTypes.PublicEvents)] Type iface)
     {