diff --git a/library/std/src/sys/io/error/unix.rs b/library/std/src/sys/io/error/unix.rs
index c545558c3867e..ce2a56fa88410 100644
--- a/library/std/src/sys/io/error/unix.rs
+++ b/library/std/src/sys/io/error/unix.rs
@@ -158,7 +158,6 @@ pub fn decode_error_kind(errno: i32) -> io::ErrorKind {
         libc::ENOENT => NotFound,
         libc::ENOMEM => OutOfMemory,
         libc::ENOSPC => StorageFull,
-        libc::ENOSYS => Unsupported,
         libc::EMLINK => TooManyLinks,
         libc::ENAMETOOLONG => InvalidFilename,
         libc::ENETDOWN => NetworkDown,
@@ -176,11 +175,16 @@ pub fn decode_error_kind(errno: i32) -> io::ErrorKind {
         libc::EXDEV => CrossesDevices,
         libc::EINPROGRESS => InProgress,
         libc::EMFILE | libc::ENFILE => TooManyOpenFiles,
-        libc::EOPNOTSUPP => Unsupported,
         libc::EIO => InputOutputError,
 
         libc::EACCES | libc::EPERM => PermissionDenied,
 
+        libc::ENOSYS => Unsupported,
+        // EOPNOTSUPP and ENOTSUP can have the same value on some systems,
+        // but different values on others (e.g. Apple), so we can't use a
+        // match clause
+        x if x == libc::EOPNOTSUPP || x == libc::ENOTSUP => Unsupported,
+
         // These two constants can have the same value on some systems,
         // but different values on others, so we can't use a match
         // clause