diff --git a/yellowstone-grpc-client/src/lib.rs b/yellowstone-grpc-client/src/lib.rs
index b44ef7a8..fe74de04 100644
--- a/yellowstone-grpc-client/src/lib.rs
+++ b/yellowstone-grpc-client/src/lib.rs
@@ -69,7 +69,7 @@ impl GeyserGrpcClient<()> {
         endpoint: E,
         x_token: Option<T>,
         tls_config: Option<ClientTlsConfig>,
-    ) -> GeyserGrpcClientResult<GeyserGrpcClient<impl Interceptor>>
+    ) -> GeyserGrpcClientResult<GeyserGrpcClient<impl Interceptor + Send + Sync>>
     where
         E: Into<Bytes>,
         T: TryInto<AsciiMetadataValue, Error = InvalidMetadataValue>,