diff --git a/build.rs b/build.rs
index 6399463..15d080f 100644
--- a/build.rs
+++ b/build.rs
@@ -6,6 +6,9 @@ fn main() {
     // Assert we haven't travelled back in time
     assert!(version().unwrap().major >= 1);
 
+    println!("cargo::rustc-check-cfg=cfg(nightly)");
+    println!("cargo::rustc-check-cfg=cfg(stable)");
+
     // Set cfg flags depending on release channel
     match version_meta().unwrap().channel {
         Channel::Stable => {
diff --git a/src/arg.rs b/src/arg.rs
index 975e860..3384651 100644
--- a/src/arg.rs
+++ b/src/arg.rs
@@ -225,8 +225,8 @@ impl std::fmt::Display for Error
 		#[cfg(nightly)] return match _v {
 		    IntErrorKind::Empty => write!(f, ": argument empty"),
 		    IntErrorKind::InvalidDigit => write!(f, ": invalid digit"),
-		    IntErrorKind::Overflow => write!(f, ": conversion would result in overflow"),
-		    IntErrorKind::Underflow => write!(f, ": conversion would result in underflow"),
+		    IntErrorKind::PosOverflow => write!(f, ": conversion would result in overflow"),
+		    IntErrorKind::NegOverflow => write!(f, ": conversion would result in underflow"),
 		    IntErrorKind::Zero => write!(f, ": found zero"),
 		    _=> Ok(()),
 		};
diff --git a/src/dir.rs b/src/dir.rs
index 0ed309a..663ac95 100644
--- a/src/dir.rs
+++ b/src/dir.rs
@@ -76,7 +76,7 @@ async fn _walk<P: AsRef<Path>+Send+Sync>(path: P, depth: usize, recurse: Option<
 		    let child = tokio::spawn(async move {
 			(__walk(&dir, depth+1, recurse, sem, output).await, dir)
 		    }.boxed());
-		    task::yield_now().await;
+		    let _ = task::yield_now().await;
 		    child
 		});
 	    }
diff --git a/src/main.rs b/src/main.rs
index f3e42ea..4a8d5c3 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -1,6 +1,4 @@
-#![cfg_attr(nightly, feature(int_error_matching))]
 #![cfg_attr(nightly, feature(linked_list_remove))]
-#![cfg_attr(nightly, feature(const_fn))]
 #![cfg_attr(nightly, feature(never_type))] 
 
 
diff --git a/src/process.rs b/src/process.rs
index d648ffe..9b74a3c 100644
--- a/src/process.rs
+++ b/src/process.rs
@@ -106,7 +106,7 @@ where U: IntoIterator<Item=V>,
 	    }
 	}
     });
-    task::yield_now().await;
+    let _ = task::yield_now().await;
     match child.await {
 	Ok(exit) => {
 	    if exit.success() {
diff --git a/src/work.rs b/src/work.rs
index f3f53a5..2a0751d 100644
--- a/src/work.rs
+++ b/src/work.rs
@@ -89,7 +89,7 @@ async fn do_work(process: impl AsRef<Process>, file: impl AsRef<OsStr>, mut prog
 	    stack
 	})
     };
-    tokio::task::yield_now().await;
+    let _ = tokio::task::yield_now().await;
     //let _ = opt_await.await;
     match process::contained_spawn(process, std::iter::once(file), tx).await {
 	Ok(_) => Ok(collector.await.expect("Child panic").into_iter()),