diff --git a/src/buildpacks.rs b/src/buildpacks.rs
index 44535ca5..5f9b78e4 100644
--- a/src/buildpacks.rs
+++ b/src/buildpacks.rs
@@ -12,17 +12,17 @@ pub(crate) enum CalculateDigestError {
     ExitStatus(String, ExitStatus),
 }
 
-pub(crate) fn calculate_digest(digest_url: &String) -> Result<String, CalculateDigestError> {
+pub(crate) fn calculate_digest(digest_url: &str) -> Result<String, CalculateDigestError> {
     let output = Command::new("crane")
         .args(["digest", digest_url])
         .output()
-        .map_err(|e| CalculateDigestError::CommandFailure(digest_url.clone(), e))?;
+        .map_err(|e| CalculateDigestError::CommandFailure(digest_url.to_owned(), e))?;
 
     if output.status.success() {
         Ok(String::from_utf8_lossy(&output.stdout).trim().to_string())
     } else {
         Err(CalculateDigestError::ExitStatus(
-            digest_url.clone(),
+            digest_url.to_owned(),
             output.status,
         ))
     }
diff --git a/src/changelog.rs b/src/changelog.rs
index bb667046..56726bd5 100644
--- a/src/changelog.rs
+++ b/src/changelog.rs
@@ -197,13 +197,13 @@ pub(crate) enum ChangelogError {
 pub(crate) fn generate_release_declarations<S: Into<String>>(
     changelog: &Changelog,
     repository: S,
-    starting_with_version: &Option<Version>,
+    starting_with_version: Option<&Version>,
 ) -> String {
     let repository = repository.into();
 
     let mut versions = changelog.releases.values().filter_map(|release| {
         if let Some(starting_version) = &starting_with_version {
-            if starting_version.le(&release.version) {
+            if (*starting_version).le(&release.version) {
                 Some(&release.version)
             } else {
                 None
@@ -394,7 +394,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
         let declarations = generate_release_declarations(
             &changelog,
             "https://github.com/olivierlacan/keep-a-changelog",
-            &None,
+            None,
         );
         assert_eq!(
             declarations,
@@ -422,7 +422,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
         let declarations = generate_release_declarations(
             &changelog,
             "https://github.com/olivierlacan/keep-a-changelog",
-            &None,
+            None,
         );
         assert_eq!(
             declarations,
@@ -438,7 +438,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
         let declarations = generate_release_declarations(
             &changelog,
             "https://github.com/olivierlacan/keep-a-changelog",
-            &None,
+            None,
         );
         assert_eq!(
             declarations,
@@ -452,7 +452,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
         let declarations = generate_release_declarations(
             &changelog,
             "https://github.com/olivierlacan/keep-a-changelog",
-            &Some(Version {
+            Some(&Version {
                 major: 1,
                 minor: 0,
                 patch: 0,
diff --git a/src/commands/prepare_release/command.rs b/src/commands/prepare_release/command.rs
index c192aef7..e7e2bfaa 100644
--- a/src/commands/prepare_release/command.rs
+++ b/src/commands/prepare_release/command.rs
@@ -116,7 +116,7 @@ pub(crate) fn execute(args: PrepareReleaseArgs) -> Result<()> {
         let release_declarations = generate_release_declarations(
             &new_changelog,
             repository_url.to_string(),
-            &declarations_starting_version,
+            declarations_starting_version.as_ref(),
         );
 
         let changelog_contents = format!("{new_changelog}\n{release_declarations}\n");