diff --git a/techtree-manager/src/collect.rs b/techtree-manager/src/collect.rs
index ef3eca1..0660eb0 100644
--- a/techtree-manager/src/collect.rs
+++ b/techtree-manager/src/collect.rs
@@ -24,7 +24,7 @@ pub async fn collect_tree(ctx: &crate::Context) -> anyhow::Result<crate::tree::T
             .await
             .with_context(|| format!("Failed fetching page {page} of the issue list"))?;
 
-        if new.len() == 0 {
+        if new.is_empty() {
             break;
         }
 
@@ -84,7 +84,7 @@ pub async fn collect_tree(ctx: &crate::Context) -> anyhow::Result<crate::tree::T
             }
 
             let dep_number = dep.number.context("Missing issue number in dependency")?;
-            if !tree.find_element_by_issue_number(dep_number).is_some() {
+            if tree.find_element_by_issue_number(dep_number).is_none() {
                 log::warn!("Found dependency from #{issue} on non-tracked issue #{dep_number}!");
             } else {
                 tree.add_dependency_by_issue_number(issue, dep_number);
@@ -133,11 +133,7 @@ fn element_from_issue(issue: &forgejo_api::structs::Issue) -> anyhow::Result<cra
             if has_completed_label {
                 crate::tree::ElementStatus::Completed
             } else if issue.assignee.is_some()
-                || issue
-                    .assignees
-                    .as_ref()
-                    .map(|v| v.len() > 0)
-                    .unwrap_or(false)
+                || issue.assignees.as_ref().is_some_and(|v| !v.is_empty())
             {
                 crate::tree::ElementStatus::Assigned
             } else {
diff --git a/techtree-manager/src/issue.rs b/techtree-manager/src/issue.rs
index 97cf9d9..51f33f0 100644
--- a/techtree-manager/src/issue.rs
+++ b/techtree-manager/src/issue.rs
@@ -57,14 +57,14 @@ pub async fn find_bot_comment(
         .rev()
         .find(|comment| comment.user.as_ref().and_then(|u| u.id) == Some(-2));
 
-    Ok(maybe_bot_comment
+    maybe_bot_comment
         .map(|c| -> anyhow::Result<_> {
             Ok(BotCommentInfo {
                 body: c.body.clone().unwrap_or("".to_owned()),
                 id: c.id.context("Missing id for the bot comment")?,
             })
         })
-        .transpose()?)
+        .transpose()
 }
 
 /// Find existing bot comment or create a new one.
@@ -115,12 +115,12 @@ pub async fn update_bot_comment_from_subtree(
     subtree: &crate::tree::Subtree<'_>,
     hash: &str,
 ) -> anyhow::Result<()> {
-    let mut mermaid = subtree.to_mermaid(&ctx.repo_url.to_string(), false);
+    let mut mermaid = subtree.to_mermaid(ctx.repo_url.as_ref(), false);
 
     // When the mermaid graph gets too big, regenerate a simplified version.
     if mermaid.len() > 4990 {
         log::info!("Mermaid graph is too big, generating simplified version...");
-        mermaid = subtree.to_mermaid(&ctx.repo_url.to_string(), true);
+        mermaid = subtree.to_mermaid(ctx.repo_url.as_ref(), true);
     }
 
     let full_text = if mermaid.len() > 4990 {
@@ -143,7 +143,7 @@ _Sorry, the partial techtree is still too big to be displayed for this element..
         )
     };
 
-    update_bot_comment(&ctx, id, full_text).await?;
+    update_bot_comment(ctx, id, full_text).await?;
 
     Ok(())
 }
@@ -157,8 +157,7 @@ pub async fn remove_stale_label(ctx: &crate::Context, issue_number: u64) -> anyh
 
     let stale_label_id = labels
         .iter()
-        .filter(|l| l.name.as_deref() == Some("Stale"))
-        .next()
+        .find(|l| l.name.as_deref() == Some("Stale"))
         .map(|l| l.id.ok_or(anyhow::anyhow!("`Stale` label has no ID")))
         .transpose()?;
 
diff --git a/techtree-manager/src/main.rs b/techtree-manager/src/main.rs
index eda6053..6a3c027 100644
--- a/techtree-manager/src/main.rs
+++ b/techtree-manager/src/main.rs
@@ -1,4 +1,7 @@
 #![allow(dead_code)]
+#![allow(clippy::useless_format)]
+#![allow(clippy::needless_return)]
+#![deny(clippy::as_conversions)]
 
 use anyhow::Context as _;
 use forgejo_api::Forgejo;
@@ -69,7 +72,7 @@ async fn run() -> anyhow::Result<()> {
         .map(|token| -> Result<_, ()> {
             let mut repo_auth_url = repo_url.clone();
             repo_auth_url.set_username("forgejo-actions")?;
-            repo_auth_url.set_password(Some(&token))?;
+            repo_auth_url.set_password(Some(token))?;
             Ok(repo_auth_url)
         })
         .transpose()
@@ -145,7 +148,9 @@ async fn run() -> anyhow::Result<()> {
     }
 
     'issues: for issue in tree.iter_issues() {
-        let subtree = tree.subtree_for_issue(issue).expect("issue from tree not found in tree");
+        let subtree = tree
+            .subtree_for_issue(issue)
+            .expect("issue from tree not found in tree");
         let hash = subtree.stable_hash();
 
         let (bot_comment, _is_new) = issue::find_or_make_bot_comment(&ctx, issue)
diff --git a/techtree-manager/src/render.rs b/techtree-manager/src/render.rs
index f18bebb..ca3682a 100644
--- a/techtree-manager/src/render.rs
+++ b/techtree-manager/src/render.rs
@@ -52,14 +52,14 @@ pub async fn render(
     std::fs::create_dir(&info.repo_dir).context("Failed creating directory for rendered graph")?;
 
     let dot_source = tree.to_dot();
-    std::fs::write(&info.dot_file(), dot_source.as_bytes())
+    std::fs::write(info.dot_file(), dot_source.as_bytes())
         .context("Failed to write `dot` source file")?;
 
     Command::new("dot")
         .args(["-T", "svg"])
         .arg("-o")
-        .arg(&info.svg_file())
-        .arg(&info.dot_file())
+        .arg(info.svg_file())
+        .arg(info.dot_file())
         .success()
         .context("Failed to generate svg graph from dot source")?;
 
diff --git a/techtree-manager/src/tree.rs b/techtree-manager/src/tree.rs
index 3ec271f..19a8a5f 100644
--- a/techtree-manager/src/tree.rs
+++ b/techtree-manager/src/tree.rs
@@ -263,7 +263,7 @@ impl Tree {
 
         for index in self.graph.node_indices() {
             mermaid.push_str(&self.graph[index].to_mermaid_node(index, None, repo_url, simple));
-            mermaid.push_str("\n");
+            mermaid.push('\n');
         }
 
         for edge in self.graph.edge_references() {
@@ -397,7 +397,7 @@ impl<'a> Subtree<'a> {
                 repo_url,
                 simple,
             ));
-            mermaid.push_str("\n");
+            mermaid.push('\n');
         }
 
         for edge in self.graph.edge_references() {
diff --git a/techtree-manager/src/wiki.rs b/techtree-manager/src/wiki.rs
index e61f931..d38a775 100644
--- a/techtree-manager/src/wiki.rs
+++ b/techtree-manager/src/wiki.rs
@@ -5,7 +5,7 @@ pub async fn update_wiki_from_tree(
     ctx: &crate::Context,
     tree: &crate::tree::Tree,
 ) -> anyhow::Result<()> {
-    let mermaid = tree.to_mermaid(&ctx.repo_url.to_string(), false);
+    let mermaid = tree.to_mermaid(ctx.repo_url.as_ref(), false);
     let wiki_text = format!(
         r##"This page is automatically updated to show the latest and greatest FAFO techtree:
 
@@ -14,7 +14,7 @@ pub async fn update_wiki_from_tree(
 ```
 "##
     );
-    update_wiki_overview(&ctx, wiki_text)
+    update_wiki_overview(ctx, wiki_text)
         .await
         .context("Failed to update the techtree wiki page")?;
     Ok(())