diff --git a/ethcore/src/client/client.rs b/ethcore/src/client/client.rs
index c7ad18dcbd3..31f8f2f25df 100644
--- a/ethcore/src/client/client.rs
+++ b/ethcore/src/client/client.rs
@@ -220,7 +220,7 @@ pub struct Client {
registrar_address: Option
,
/// A closure to call when we want to restart the client
- exit_handler: Mutex