diff --git a/src/clone.rs b/src/clone.rs
index c872fba..a3d1af7 100644
--- a/src/clone.rs
+++ b/src/clone.rs
@@ -23,7 +23,6 @@ use std::ptr;
 
 impl<V: Copy, const N: usize> Clone for Stack<V, N> {
     /// Clone it.
-    #[must_use]
     fn clone(&self) -> Self {
         let mut s: Self = Self::new();
         s.next = self.next;
diff --git a/src/ctors.rs b/src/ctors.rs
index 41736e9..ac3004c 100644
--- a/src/ctors.rs
+++ b/src/ctors.rs
@@ -24,7 +24,6 @@ use std::mem::MaybeUninit;
 impl<V: Copy, const N: usize> Default for Stack<V, N> {
     /// Make a default empty [`Stack`].
     #[inline]
-    #[must_use]
     fn default() -> Self {
         Self::new()
     }
diff --git a/src/debug.rs b/src/debug.rs
index c6a1dc4..419cf82 100644
--- a/src/debug.rs
+++ b/src/debug.rs
@@ -23,13 +23,13 @@ use std::fmt;
 use std::fmt::{Debug, Display, Formatter};
 
 impl<V: Display + Copy, const N: usize> Display for Stack<V, N> {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         <&Self as Debug>::fmt(&self, f)
     }
 }
 
 impl<V: Display + Copy, const N: usize> Debug for Stack<V, N> {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         let mut parts = vec![];
         for v in self.iter() {
             parts.push(format!("{v}"));
diff --git a/src/iterators.rs b/src/iterators.rs
index 66481e7..ab325f9 100644
--- a/src/iterators.rs
+++ b/src/iterators.rs
@@ -25,7 +25,6 @@ impl<V: Copy, const N: usize> Iterator for IntoIter<V, N> {
     type Item = V;
 
     #[inline]
-    #[must_use]
     fn next(&mut self) -> Option<Self::Item> {
         if self.pos >= self.next {
             None
@@ -37,7 +36,7 @@ impl<V: Copy, const N: usize> Iterator for IntoIter<V, N> {
     }
 }
 
-impl<'a, V: Copy + 'a, const N: usize> Stack<V, N> {
+impl<V: Copy, const N: usize> Stack<V, N> {
     /// Into-iterate them.
     #[inline]
     pub const fn into_iter(&self) -> IntoIter<V, N> {
@@ -53,7 +52,6 @@ impl<'a, V: Copy, const N: usize> Iterator for Iter<'a, V, N> {
     type Item = &'a V;
 
     #[inline]
-    #[must_use]
     fn next(&mut self) -> Option<Self::Item> {
         if self.pos >= self.next {
             None
@@ -67,10 +65,10 @@ impl<'a, V: Copy, const N: usize> Iterator for Iter<'a, V, N> {
     }
 }
 
-impl<'a, V: Copy + 'a, const N: usize> Stack<V, N> {
+impl<V: Copy, const N: usize> Stack<V, N> {
     /// Iterate them.
     #[inline]
-    pub const fn iter(&self) -> Iter<V, N> {
+    pub const fn iter(&self) -> Iter<'_, V, N> {
         Iter {
             pos: 0,
             next: self.next,
diff --git a/src/lib.rs b/src/lib.rs
index c721403..35615f8 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -38,10 +38,12 @@
 //! to a panic.
 
 #![doc(html_root_url = "https://docs.rs/microstack/0.0.0")]
-#![deny(warnings)]
+#![deny(rust_2018_idioms, unused, deprecated)]
 #![warn(clippy::all, clippy::pedantic, clippy::nursery, clippy::cargo)]
 #![allow(clippy::multiple_inherent_impl)]
 #![allow(clippy::multiple_crate_versions)]
+#![allow(clippy::missing_const_for_fn)]
+#![allow(clippy::iter_without_into_iter)]
 
 use std::marker::PhantomData;
 
diff --git a/src/serialization.rs b/src/serialization.rs
index 651f9f1..45e4976 100644
--- a/src/serialization.rs
+++ b/src/serialization.rs
@@ -43,7 +43,7 @@ struct Vi<V, const N: usize>(PhantomData<V>);
 impl<'de, V: Copy + Deserialize<'de>, const N: usize> Visitor<'de> for Vi<V, N> {
     type Value = Stack<V, N>;
 
-    fn expecting(&self, formatter: &mut Formatter) -> std::fmt::Result {
+    fn expecting(&self, formatter: &mut Formatter<'_>) -> std::fmt::Result {
         formatter.write_str("a Stack")
     }