diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 5e79912f..6e6aede7 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -35,16 +35,16 @@ repos:
     hooks:
       - id: markdownlint-cli2
   - repo: https://github.com/shellcheck-py/shellcheck-py
-    rev: v0.9.0.5
+    rev: v0.9.0.6
     hooks:
       - id: shellcheck
   - repo: https://github.com/codespell-project/codespell
-    rev: v2.2.5
+    rev: v2.2.6
     hooks:
       - id: codespell
         args: [--ignore-words=.codespellignore]
   - repo: https://github.com/sirosen/check-jsonschema
-    rev: 0.26.3
+    rev: 0.27.0
     hooks:
       - id: check-github-actions
       - id: check-github-workflows
diff --git a/src/codec/tcp.rs b/src/codec/tcp.rs
index e3ee35ba..547c0cb1 100644
--- a/src/codec/tcp.rs
+++ b/src/codec/tcp.rs
@@ -295,7 +295,7 @@ mod tests {
             assert_eq!(buf[5], 0x6);
             assert_eq!(buf[6], UNIT_ID);
 
-            _ = buf.split_to(7);
+            drop(buf.split_to(7));
             let pdu: Bytes = req.try_into().unwrap();
             assert_eq!(buf, pdu);
         }
diff --git a/src/lib.rs b/src/lib.rs
index 1c0713a8..c1be935c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,15 +1,19 @@
 // SPDX-FileCopyrightText: Copyright (c) 2017-2023 slowtec GmbH <post@slowtec.de>
 // SPDX-License-Identifier: MIT OR Apache-2.0
 
-#![warn(rustdoc::broken_intra_doc_links)]
 #![doc = include_str!("../README.md")]
-#![warn(rust_2018_idioms)]
-#![warn(rust_2021_compatibility)]
+// Opt-in for allowed-by-default lints (in alphabetical order)
+// See also: <https://doc.rust-lang.org/rustc/lints>
+#![warn(future_incompatible)]
+#![warn(let_underscore)]
 #![warn(missing_debug_implementations)]
 //#![warn(missing_docs)] // TODO
+#![warn(rust_2018_idioms)]
+#![warn(rust_2021_compatibility)]
 #![warn(unreachable_pub)]
 #![warn(unsafe_code)]
-#![warn(rustdoc::broken_intra_doc_links)]
+#![warn(unused)]
+// Clippy lints
 #![warn(clippy::pedantic)]
 // Additional restrictions
 #![warn(clippy::clone_on_ref_ptr)]