diff --git a/Cargo.toml b/Cargo.toml
index 21d75145..992d8ac8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,11 +1,11 @@
 [workspace]
-resolver = "2"
+resolver = "3"
 
 [workspace.package]
 repository = "https://github.com/rust-cli/config-rs"
 license = "MIT OR Apache-2.0"
-edition = "2018"
-rust-version = "1.76.0"  # MSRV
+edition = "2024"
+rust-version = "1.85.0"  # MSRV
 include = [
   "build.rs",
   "src/**/*",
diff --git a/examples/async_source/main.rs b/examples/async_source/main.rs
index ff76013c..9964b730 100644
--- a/examples/async_source/main.rs
+++ b/examples/async_source/main.rs
@@ -2,9 +2,9 @@ use std::{error::Error, fmt::Debug};
 
 use async_trait::async_trait;
 use config::{
-    builder::AsyncState, AsyncSource, ConfigBuilder, ConfigError, FileFormat, Format, Map,
+    AsyncSource, ConfigBuilder, ConfigError, FileFormat, Format, Map, builder::AsyncState,
 };
-use futures::{select, FutureExt};
+use futures::{FutureExt, select};
 use warp::Filter;
 
 // Example below presents sample configuration server and client.
diff --git a/examples/custom_file_format/main.rs b/examples/custom_file_format/main.rs
index 1d6b30f9..2650664b 100644
--- a/examples/custom_file_format/main.rs
+++ b/examples/custom_file_format/main.rs
@@ -52,7 +52,7 @@ impl Format for PemFile {
                 return Err(Box::new(Error::new(
                     ErrorKind::InvalidData,
                     "PEM file did not contain a Private or Public key",
-                )))
+                )));
             }
         };
 
diff --git a/examples/env-list/main.rs b/examples/env-list/main.rs
index 8fc7f9fa..e7968ca2 100644
--- a/examples/env-list/main.rs
+++ b/examples/env-list/main.rs
@@ -1,11 +1,12 @@
 use config::Config;
+
 #[derive(Debug, Default, serde::Deserialize, PartialEq, Eq)]
 struct AppConfig {
     list: Vec<String>,
 }
 
 fn main() {
-    std::env::set_var("APP_LIST", "Hello World");
+    // e.g. set `APP_LIST="Hello World"
 
     let config = Config::builder()
         .add_source(
@@ -20,6 +21,4 @@ fn main() {
     let app: AppConfig = config.try_deserialize().unwrap();
 
     assert_eq!(app.list, vec![String::from("Hello"), String::from("World")]);
-
-    std::env::remove_var("APP_LIST");
 }
diff --git a/examples/watch/main.rs b/examples/watch/main.rs
index 69200a10..6b2cce33 100644
--- a/examples/watch/main.rs
+++ b/examples/watch/main.rs
@@ -1,8 +1,8 @@
 use std::collections::HashMap;
 use std::path::Path;
-use std::sync::mpsc::channel;
 use std::sync::OnceLock;
 use std::sync::RwLock;
+use std::sync::mpsc::channel;
 use std::time::Duration;
 
 use config::{Config, File};
diff --git a/src/de.rs b/src/de.rs
index 85fe2f18..bc46d34d 100644
--- a/src/de.rs
+++ b/src/de.rs
@@ -243,7 +243,7 @@ impl<'de> de::MapAccess<'de> for MapAccess {
     where
         K: de::DeserializeSeed<'de>,
     {
-        if let Some((ref key_s, _)) = self.elements.front() {
+        if let Some((key_s, _)) = self.elements.front() {
             let key_de = Value::new(None, key_s as &str);
             let key = de::DeserializeSeed::deserialize(seed, key_de)?;
 
diff --git a/src/env.rs b/src/env.rs
index 03ca997d..c647da30 100644
--- a/src/env.rs
+++ b/src/env.rs
@@ -4,11 +4,11 @@ use std::ffi::OsString;
 #[cfg(feature = "convert-case")]
 use convert_case::{Case, Casing};
 
+use crate::ConfigError;
 use crate::error::Result;
 use crate::map::Map;
 use crate::source::Source;
 use crate::value::{Value, ValueKind};
-use crate::ConfigError;
 
 /// An environment source collects a dictionary of environment variables values into a hierarchical
 /// config Value type. We have to be aware how the config tree is created from the environment
diff --git a/src/file/format/corn.rs b/src/file/format/corn.rs
index f188df16..0fd7e728 100644
--- a/src/file/format/corn.rs
+++ b/src/file/format/corn.rs
@@ -1,5 +1,5 @@
-use crate::value::{Value, ValueKind};
-use crate::{format, Map};
+use crate::value::{Value, ValueKind};
+use crate::{Map, format};
 use std::error::Error;
 
 pub(crate) fn parse(
diff --git a/src/file/format/mod.rs b/src/file/format/mod.rs
index bb3df49d..4035c6f7 100644
--- a/src/file/format/mod.rs
+++ b/src/file/format/mod.rs
@@ -1,7 +1,7 @@
 use std::error::Error;
 
 use crate::map::Map;
-use crate::{file::FileStoredFormat, value::Value, Format};
+use crate::{Format, file::FileStoredFormat, value::Value};
 
 #[cfg(feature = "toml")]
 mod toml;
diff --git a/src/file/mod.rs b/src/file/mod.rs
index 72e0a361..4a33cee7 100644
--- a/src/file/mod.rs
+++ b/src/file/mod.rs
@@ -5,11 +5,11 @@ use std::fmt::Debug;
 use std::path::{Path, PathBuf};
 
 use self::source::FileSource;
+use crate::Format;
 use crate::error::{ConfigError, Result};
 use crate::map::Map;
 use crate::source::Source;
 use crate::value::Value;
-use crate::Format;
 
 pub use self::format::FileFormat;
 pub use self::source::file::FileSourceFile;
diff --git a/src/file/source/file.rs b/src/file/source/file.rs
index d80c6ef6..e60fc521 100644
--- a/src/file/source/file.rs
+++ b/src/file/source/file.rs
@@ -4,7 +4,7 @@ use std::fs;
 use std::io;
 use std::path::PathBuf;
 
-use crate::file::{source::FileSourceResult, FileFormat, FileSource, FileStoredFormat, Format};
+use crate::file::{FileFormat, FileSource, FileStoredFormat, Format, source::FileSourceResult};
 
 /// Describes a file sourced from a file
 #[derive(Clone, Debug)]
diff --git a/src/file/source/mod.rs b/src/file/source/mod.rs
index 7abc7351..d79ad993 100644
--- a/src/file/source/mod.rs
+++ b/src/file/source/mod.rs
@@ -4,7 +4,7 @@ pub(crate) mod string;
 use std::error::Error;
 use std::fmt::Debug;
 
-use crate::{file::FileStoredFormat, Format};
+use crate::{Format, file::FileStoredFormat};
 
 /// Describes where the [`File`][super::File] is sourced
 pub trait FileSource<T>: Debug + Clone
diff --git a/src/file/source/string.rs b/src/file/source/string.rs
index 89300d4a..96d2e90a 100644
--- a/src/file/source/string.rs
+++ b/src/file/source/string.rs
@@ -1,9 +1,9 @@
 use std::error::Error;
 
 use crate::{
+    Format,
     file::source::FileSourceResult,
     file::{FileSource, FileStoredFormat},
-    Format,
 };
 
 /// Describes a file sourced from a string
diff --git a/src/ser.rs b/src/ser.rs
index 211717a5..56d0b0d2 100644
--- a/src/ser.rs
+++ b/src/ser.rs
@@ -3,9 +3,9 @@ use std::fmt::Write as _;
 
 use serde_core::ser;
 
+use crate::Config;
 use crate::error::{ConfigError, Result};
 use crate::value::{Value, ValueKind};
-use crate::Config;
 
 #[derive(Default, Debug)]
 pub(crate) struct ConfigSerializer {
@@ -276,7 +276,7 @@ impl ser::SerializeSeq for SeqSerializer<'_> {
             _ => {
                 return Err(ConfigError::Message(
                     "config-rs internal error (ser._element but last not Seq!".to_owned(),
-                ))
+                ));
             }
         };
         Ok(())
diff --git a/tests/testsuite/errors.rs b/tests/testsuite/errors.rs
index e8a1dbdf..9fc1e4bd 100644
--- a/tests/testsuite/errors.rs
+++ b/tests/testsuite/errors.rs
@@ -82,7 +82,7 @@ fn test_root_not_table() {
             "invalid type: boolean `false`, expected a map",
             format!("{cause}")
         ),
-        _ => panic!("Wrong error: {:?}", e),
+        _ => panic!("Wrong error: {e:?}"),
     }
 }
 
@@ -304,7 +304,12 @@ fn test_value_deserialize_enum() {
 
     let array_v: Value = vec![100, 100].into();
     let array_d = array_v.try_deserialize::<Diode>();
-    assert_data_eq!(array_d.unwrap_err().to_string(), str!["value of enum Diode should be represented by either string or table with exactly one key"]);
+    assert_data_eq!(
+        array_d.unwrap_err().to_string(),
+        str![
+            "value of enum Diode should be represented by either string or table with exactly one key"
+        ]
+    );
 
     let confused_v: Value = [
         ("Brightness".to_owned(), 100.into()),
@@ -315,7 +320,12 @@ fn test_value_deserialize_enum() {
     .collect::<Map<String, Value>>()
     .into();
     let confused_d = confused_v.try_deserialize::<Diode>();
-    assert_data_eq!(confused_d.unwrap_err().to_string(), str!["value of enum Diode should be represented by either string or table with exactly one key"]);
+    assert_data_eq!(
+        confused_d.unwrap_err().to_string(),
+        str![
+            "value of enum Diode should be represented by either string or table with exactly one key"
+        ]
+    );
 }
 
 #[test]
@@ -359,7 +369,7 @@ fn test_deserialize_invalid_type() {
     {
         assert_eq!(path, "place.name");
     } else {
-        panic!("Wrong error {:?}", e);
+        panic!("Wrong error {e:?}");
     }
 }
 
@@ -400,7 +410,7 @@ fn test_deserialize_invalid_type_file() {
     {
         assert_eq!(path, "place.name");
     } else {
-        panic!("Wrong error {:?}", e);
+        panic!("Wrong error {e:?}");
     }
 }
 
diff --git a/tests/testsuite/file_corn.rs b/tests/testsuite/file_corn.rs
index a7488a8c..194ac34f 100644
--- a/tests/testsuite/file_corn.rs
+++ b/tests/testsuite/file_corn.rs
@@ -139,7 +139,10 @@ fn test_override_uppercase_value_for_struct() {
         FOO: String,
     }
 
-    std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -205,7 +208,10 @@ fn test_override_lowercase_value_for_struct() {
         bar: String,
     }
 
-    std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -253,7 +259,10 @@ fn test_override_uppercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -283,7 +292,10 @@ fn test_override_lowercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
diff --git a/tests/testsuite/file_ini.rs b/tests/testsuite/file_ini.rs
index 59cf2b1b..00099f81 100644
--- a/tests/testsuite/file_ini.rs
+++ b/tests/testsuite/file_ini.rs
@@ -93,7 +93,10 @@ fn test_override_uppercase_value_for_struct() {
         FOO: String,
     }
 
-    std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -148,7 +151,10 @@ fn test_override_lowercase_value_for_struct() {
         bar: String,
     }
 
-    std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -186,7 +192,10 @@ fn test_override_uppercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -214,7 +223,10 @@ fn test_override_lowercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
diff --git a/tests/testsuite/file_json.rs b/tests/testsuite/file_json.rs
index 90a1483d..3a71681f 100644
--- a/tests/testsuite/file_json.rs
+++ b/tests/testsuite/file_json.rs
@@ -132,7 +132,10 @@ fn test_override_uppercase_value_for_struct() {
         FOO: String,
     }
 
-    std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -199,7 +202,10 @@ fn test_override_lowercase_value_for_struct() {
         bar: String,
     }
 
-    std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -247,7 +253,10 @@ fn test_override_uppercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -277,7 +286,10 @@ fn test_override_lowercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
diff --git a/tests/testsuite/file_json5.rs b/tests/testsuite/file_json5.rs
index b199c390..bcb53552 100644
--- a/tests/testsuite/file_json5.rs
+++ b/tests/testsuite/file_json5.rs
@@ -140,7 +140,10 @@ fn test_override_uppercase_value_for_struct() {
         FOO: String,
     }
 
-    std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -207,7 +210,10 @@ fn test_override_lowercase_value_for_struct() {
         bar: String,
     }
 
-    std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -256,7 +262,10 @@ fn test_override_uppercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -286,7 +295,10 @@ fn test_override_lowercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
diff --git a/tests/testsuite/file_ron.rs b/tests/testsuite/file_ron.rs
index e6376f40..fa791167 100644
--- a/tests/testsuite/file_ron.rs
+++ b/tests/testsuite/file_ron.rs
@@ -135,7 +135,10 @@ fn test_override_uppercase_value_for_struct() {
         FOO: String,
     }
 
-    std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -202,7 +205,10 @@ fn test_override_lowercase_value_for_struct() {
         bar: String,
     }
 
-    std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -251,7 +257,10 @@ fn test_override_uppercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -281,7 +290,10 @@ fn test_override_lowercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
diff --git a/tests/testsuite/file_toml.rs b/tests/testsuite/file_toml.rs
index 70835c64..7a78c08a 100644
--- a/tests/testsuite/file_toml.rs
+++ b/tests/testsuite/file_toml.rs
@@ -182,7 +182,10 @@ fn test_override_uppercase_value_for_struct() {
         FOO: String,
     }
 
-    std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -286,7 +289,10 @@ fn test_override_lowercase_value_for_struct() {
         bar: String,
     }
 
-    std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -372,7 +378,10 @@ fn test_override_uppercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -400,7 +409,10 @@ fn test_override_lowercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
diff --git a/tests/testsuite/file_yaml.rs b/tests/testsuite/file_yaml.rs
index caed24fa..19e45902 100644
--- a/tests/testsuite/file_yaml.rs
+++ b/tests/testsuite/file_yaml.rs
@@ -168,7 +168,10 @@ fn test_override_uppercase_value_for_struct() {
         FOO: String,
     }
 
-    std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APP_FOO", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -231,7 +234,10 @@ fn test_override_lowercase_value_for_struct() {
         bar: String,
     }
 
-    std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("config_foo", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -275,7 +281,10 @@ fn test_override_uppercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("APPS_BAR", "I HAVE BEEN OVERRIDDEN_WITH_UPPER_CASE");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -303,7 +312,10 @@ fn test_override_lowercase_value_for_enums() {
         Bar(String),
     }
 
-    std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    // SAFETY: pure rust
+    unsafe {
+        std::env::set_var("test_bar", "I have been overridden_with_lower_case");
+    }
 
     let cfg = Config::builder()
         .add_source(File::from_str(
@@ -358,7 +370,9 @@ inner_vec:
     assert!(result.is_err());
     assert_data_eq!(
         result.unwrap_err().to_string(),
-        str!["Cannot parse Array([Integer(1), Integer(2)]) because it is an unsupported hash key type"]
+        str![
+            "Cannot parse Array([Integer(1), Integer(2)]) because it is an unsupported hash key type"
+        ]
     );
 }
 
diff --git a/tests/testsuite/merge.rs b/tests/testsuite/merge.rs
index d2b8f935..986a5572 100644
--- a/tests/testsuite/merge.rs
+++ b/tests/testsuite/merge.rs
@@ -366,6 +366,8 @@ Settings {
     let res = cfg.try_deserialize::<Settings>();
     assert_data_eq!(
         res.unwrap_err().to_string(),
-        str!["invalid type: integer `42`, expected struct Profile for key `profile.int_to_non_empty`"]
+        str![
+            "invalid type: integer `42`, expected struct Profile for key `profile.int_to_non_empty`"
+        ]
     );
 }
diff --git a/tests/testsuite/weird_keys.rs b/tests/testsuite/weird_keys.rs
index ad2a49c6..df81e1d7 100644
--- a/tests/testsuite/weird_keys.rs
+++ b/tests/testsuite/weird_keys.rs
@@ -16,10 +16,10 @@ where
         .add_source(File::from_str(config, format))
         .build();
 
-    assert!(cfg.is_ok(), "Config could not be built: {:?}", cfg);
+    assert!(cfg.is_ok(), "Config could not be built: {cfg:?}");
     let cfg = cfg.unwrap().try_deserialize();
 
-    assert!(cfg.is_ok(), "Config could not be transformed: {:?}", cfg);
+    assert!(cfg.is_ok(), "Config could not be transformed: {cfg:?}");
     let cfg: T = cfg.unwrap();
     cfg
 }