diff --git a/library/std/src/sys/yggdrasil/mod.rs b/library/std/src/sys/yggdrasil/mod.rs
index 31a0dcc36ac..4ebf0349e25 100644
--- a/library/std/src/sys/yggdrasil/mod.rs
+++ b/library/std/src/sys/yggdrasil/mod.rs
@@ -88,6 +88,9 @@ fn cvt_io_err(e: OsError) -> crate::io::Error {
         OsError::InvalidArgument => {
             crate::io::const_io_error!(ErrorKind::InvalidInput, "invalid argument")
         }
+        OsError::NotImplemented => {
+            crate::io::const_io_error!(ErrorKind::Unsupported, "feature not implemented")
+        }
     }
 }