diff --git a/src/work.rs b/src/work.rs
index ee0ac21..f5f80b6 100644
--- a/src/work.rs
+++ b/src/work.rs
@@ -149,7 +149,9 @@ where I: IntoIterator<Item=T>,
 						    let task = progress.add_task(format!("{:?}", filename.as_ref()));
 						    future::join(task, worker).await
 						} else {
-						    (Option::<!>::None, do_work(process.as_ref(), &filename, ()).await)
+						    #[cfg(nightly)] type NoReturn = !;
+						    #[cfg(not(nightly))] type NoReturn = ();
+						    (Option::<NoReturn>::None, do_work(process.as_ref(), &filename, ()).await)
 						}
 					    }
 					};
@@ -165,7 +167,13 @@ where I: IntoIterator<Item=T>,
 					    if #[cfg(feature="progress")] {
 						worker.0.ok().into()
 					    } else {
-						std::marker::PhantomData::<!>
+						cfg_if!{
+						    if #[cfg(nightly)] {
+							std::marker::PhantomData::<!>
+						    } else {
+							std::marker::PhantomData::<()>
+						    }
+						}
 					    }
 					}
 				    };