diff --git a/.github/workflows/workspace.yml b/.github/workflows/workspace.yml
index d321c825..1cd3f63f 100644
--- a/.github/workflows/workspace.yml
+++ b/.github/workflows/workspace.yml
@@ -28,6 +28,6 @@ jobs:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@master
         with:
-          toolchain: 1.72.0
+          toolchain: 1.81.0
           components: clippy
       - run: cargo clippy --all --all-features -- -D warnings
diff --git a/aes-siv/src/lib.rs b/aes-siv/src/lib.rs
index 48360e4b..f9fcd020 100644
--- a/aes-siv/src/lib.rs
+++ b/aes-siv/src/lib.rs
@@ -110,6 +110,8 @@ pub type Nonce<NonceSize = U16> = Array<u8, NonceSize>;
 /// AES-SIV tags (i.e. the Synthetic Initialization Vector value)
 pub type Tag = Array<u8, U16>;
 
+/// Convinience wrapper around `Siv` interface.
+///
 /// The `SivAead` type wraps the more powerful `Siv` interface in a more
 /// commonly used Authenticated Encryption with Associated Data (AEAD) API,
 /// which accepts a key, nonce, and associated data when encrypting/decrypting.
diff --git a/ccm/src/lib.rs b/ccm/src/lib.rs
index 352a73ac..77114363 100644
--- a/ccm/src/lib.rs
+++ b/ccm/src/lib.rs
@@ -85,13 +85,13 @@ impl<T: private::SealedNonce> NonceSize for T {}
 /// Type parameters:
 /// - `C`: block cipher.
 /// - `M`: size of MAC tag in bytes, valid values:
-/// [`U4`][consts::U4], [`U6`][consts::U6], [`U8`][consts::U8],
-/// [`U10`][consts::U10], [`U12`][consts::U12], [`U14`][consts::U14],
-/// [`U16`][consts::U16].
+///   [`U4`][consts::U4], [`U6`][consts::U6], [`U8`][consts::U8],
+///   [`U10`][consts::U10], [`U12`][consts::U12], [`U14`][consts::U14],
+///   [`U16`][consts::U16].
 /// - `N`: size of nonce, valid values:
-/// [`U7`][consts::U7], [`U8`][consts::U8], [`U9`][consts::U9],
-/// [`U10`][consts::U10], [`U11`][consts::U11], [`U12`][consts::U12],
-/// [`U13`][consts::U13].
+///   [`U7`][consts::U7], [`U8`][consts::U8], [`U9`][consts::U9],
+///   [`U10`][consts::U10], [`U11`][consts::U11], [`U12`][consts::U12],
+///   [`U13`][consts::U13].
 #[derive(Clone)]
 pub struct Ccm<C, M, N>
 where
@@ -335,7 +335,7 @@ fn fill_aad_header(adata_len: usize) -> (usize, Array<u8, U16>) {
     let n = if adata_len < 0xFF00 {
         b[..2].copy_from_slice(&(adata_len as u16).to_be_bytes());
         2
-    } else if adata_len <= core::u32::MAX as usize {
+    } else if adata_len <= u32::MAX as usize {
         b[0] = 0xFF;
         b[1] = 0xFE;
         b[2..6].copy_from_slice(&(adata_len as u32).to_be_bytes());
diff --git a/ccm/src/private.rs b/ccm/src/private.rs
index 658ee028..53a12883 100644
--- a/ccm/src/private.rs
+++ b/ccm/src/private.rs
@@ -16,7 +16,7 @@ pub trait SealedNonce: Unsigned {
         // compiler should be able to completely optimize it out
         let l = Self::get_l() as u128;
         let v = (1 << (8 * l)) - 1;
-        core::cmp::min(v, core::usize::MAX as u128) as usize
+        core::cmp::min(v, usize::MAX as u128) as usize
     }
 }
 
diff --git a/ccm/tests/mod.rs b/ccm/tests/mod.rs
index 4270a92e..96d3c985 100644
--- a/ccm/tests/mod.rs
+++ b/ccm/tests/mod.rs
@@ -18,11 +18,11 @@ fn test_data_len_check() {
     let nonce = Array(nonce);
     let c = Cipher::new(&key);
 
-    let mut buf1 = [1; core::u16::MAX as usize];
+    let mut buf1 = [1; u16::MAX as usize];
     let res = c.encrypt_in_place_detached(&nonce, &[], &mut buf1);
     assert!(res.is_ok());
 
-    let mut buf2 = [1; core::u16::MAX as usize + 1];
+    let mut buf2 = [1; u16::MAX as usize + 1];
     let res = c.encrypt_in_place_detached(&nonce, &[], &mut buf2);
     assert!(res.is_err());
 }
diff --git a/chacha20poly1305/src/cipher.rs b/chacha20poly1305/src/cipher.rs
index 83dcd271..68cb83f7 100644
--- a/chacha20poly1305/src/cipher.rs
+++ b/chacha20poly1305/src/cipher.rs
@@ -16,7 +16,7 @@ const BLOCK_SIZE: usize = 64;
 
 /// Maximum number of blocks that can be encrypted with ChaCha20 before the
 /// counter overflows.
-const MAX_BLOCKS: usize = core::u32::MAX as usize;
+const MAX_BLOCKS: usize = u32::MAX as usize;
 
 /// ChaCha20Poly1305 instantiated with a particular nonce
 pub(crate) struct Cipher<C>