diff --git a/idptoken/grpc_client.go b/idptoken/grpc_client.go
index 824f54a..f3f1f25 100644
--- a/idptoken/grpc_client.go
+++ b/idptoken/grpc_client.go
@@ -126,10 +126,12 @@ func (c *GRPCClient) IntrospectToken(
 		req.ScopeFilter[i] = &pb.IntrospectionScopeFilter{ResourceNamespace: scopeFilter[i].ResourceNamespace}
 	}
 
-	ctx = metadata.AppendToOutgoingContext(ctx, grpcMetaAuthorization, makeBearerToken(accessToken))
+	var md = make(metadata.MD)
+	md.Append(grpcMetaAuthorization, makeBearerToken(accessToken))
 	if c.requestIDProvider != nil {
-		ctx = metadata.AppendToOutgoingContext(ctx, grpcMetaRequestID, c.requestIDProvider(ctx))
+		md.Append(grpcMetaRequestID, c.requestIDProvider(ctx))
 	}
+	ctx = metadata.NewOutgoingContext(ctx, md)
 
 	var resp *pb.IntrospectTokenResponse
 	if err := c.do(ctx, "IDPTokenService/IntrospectToken", func(ctx context.Context) error {