diff --git a/src/libstd/sync/mpsc/shared.rs b/src/libstd/sync/mpsc/shared.rs
index 2b0393573fd..c4e929624d7 100644
--- a/src/libstd/sync/mpsc/shared.rs
+++ b/src/libstd/sync/mpsc/shared.rs
@@ -12,7 +12,6 @@ use self::StartResult::*;
 
 use core::cmp;
 use core::intrinsics::abort;
-use core::isize;
 
 use crate::cell::UnsafeCell;
 use crate::ptr;
diff --git a/src/libstd/sync/mpsc/stream.rs b/src/libstd/sync/mpsc/stream.rs
index 2e3270e81fc..f33493ee0c9 100644
--- a/src/libstd/sync/mpsc/stream.rs
+++ b/src/libstd/sync/mpsc/stream.rs
@@ -11,7 +11,6 @@ use self::Message::*;
 pub use self::UpgradeResult::*;
 
 use core::cmp;
-use core::isize;
 
 use crate::cell::UnsafeCell;
 use crate::ptr;
diff --git a/src/libstd/sync/mpsc/sync.rs b/src/libstd/sync/mpsc/sync.rs
index 79e86817154..3e2050799cc 100644
--- a/src/libstd/sync/mpsc/sync.rs
+++ b/src/libstd/sync/mpsc/sync.rs
@@ -26,7 +26,6 @@ use self::Blocker::*;
 pub use self::Failure::*;
 
 use core::intrinsics::abort;
-use core::isize;
 use core::mem;
 use core::ptr;
 
diff --git a/src/libstd/sys/hermit/thread.rs b/src/libstd/sys/hermit/thread.rs
index c7bea168f34..34f88eea0d7 100644
--- a/src/libstd/sys/hermit/thread.rs
+++ b/src/libstd/sys/hermit/thread.rs
@@ -6,7 +6,6 @@ use crate::io;
 use crate::mem;
 use crate::sys::hermit::abi;
 use crate::time::Duration;
-use core::u32;
 
 pub type Tid = abi::Tid;