diff --git a/lighthouse/environment/src/lib.rs b/lighthouse/environment/src/lib.rs
index e88dabe9f0a..80539f88a84 100644
--- a/lighthouse/environment/src/lib.rs
+++ b/lighthouse/environment/src/lib.rs
@@ -396,7 +396,7 @@ impl<E: EthSpec> Environment<E> {
             }
             future::Either::Left((Err(e), _)) => Err(e.into()),
             future::Either::Right(((res, _, _), _)) => {
-                res.ok_or("Handler channel closed".to_string())
+                res.ok_or_else(|| "Handler channel closed".to_string())
             }
         }
     }