diff --git a/serde/src/lib.rs b/serde/src/lib.rs
index eb7aa326..2d7a4ff3 100644
--- a/serde/src/lib.rs
+++ b/serde/src/lib.rs
@@ -65,7 +65,7 @@
 #![cfg_attr(feature = "alloc", feature(alloc))]
 #![cfg_attr(feature = "collections", feature(collections))]
 #![cfg_attr(feature = "cargo-clippy", allow(linkedlist, type_complexity, doc_markdown))]
-#![deny(missing_docs)]
+#![deny(missing_docs, unused_imports)]
 
 #[cfg(feature = "collections")]
 extern crate collections;
diff --git a/serde/src/ser/impls.rs b/serde/src/ser/impls.rs
index 4f817760..a9bfaf09 100644
--- a/serde/src/ser/impls.rs
+++ b/serde/src/ser/impls.rs
@@ -14,11 +14,7 @@ use collections::borrow::ToOwned;
 #[cfg(feature = "std")]
 use core::hash::{Hash, BuildHasher};
 #[cfg(feature = "std")]
-use std::net;
-#[cfg(any(feature = "std", feature = "unstable"))]
-use core::ops;
-#[cfg(feature = "std")]
-use std::path;
+use std::{net, ops, path};
 #[cfg(feature = "std")]
 use std::ffi::{CString, CStr, OsString, OsStr};
 #[cfg(feature = "std")]