diff --git a/lib/src/dag_walk.rs b/lib/src/dag_walk.rs
index fcce60671..782c04030 100644
--- a/lib/src/dag_walk.rs
+++ b/lib/src/dag_walk.rs
@@ -43,10 +43,10 @@ where
 }
 
 /// Returns neighbors before the node itself.
-pub fn topo_order_reverse<'a, T, ID, II, NI>(
+pub fn topo_order_reverse<T, ID, II, NI>(
     start: II,
-    id_fn: Box<dyn Fn(&T) -> ID + 'a>,
-    mut neighbors_fn: Box<dyn FnMut(&T) -> NI + 'a>,
+    id_fn: impl Fn(&T) -> ID,
+    mut neighbors_fn: impl FnMut(&T) -> NI,
 ) -> Vec<T>
 where
     T: Hash + Eq + Clone,
@@ -215,11 +215,8 @@ mod tests {
             'C' => vec!['B'],
         };
 
-        let common = topo_order_reverse(
-            vec!['C'],
-            Box::new(|node| *node),
-            Box::new(move |node| neighbors[node].clone()),
-        );
+        let common =
+            topo_order_reverse(vec!['C'], |node| *node, move |node| neighbors[node].clone());
 
         assert_eq!(common, vec!['C', 'B', 'A']);
     }
@@ -245,11 +242,8 @@ mod tests {
             'F' => vec!['E', 'D'],
         };
 
-        let common = topo_order_reverse(
-            vec!['F'],
-            Box::new(|node| *node),
-            Box::new(move |node| neighbors[node].clone()),
-        );
+        let common =
+            topo_order_reverse(vec!['F'], |node| *node, move |node| neighbors[node].clone());
 
         assert_eq!(common, vec!['F', 'E', 'D', 'C', 'B', 'A']);
     }
@@ -279,8 +273,8 @@ mod tests {
 
         let common = topo_order_reverse(
             vec!['F', 'C'],
-            Box::new(|node| *node),
-            Box::new(move |node| neighbors[node].clone()),
+            |node| *node,
+            move |node| neighbors[node].clone(),
         );
 
         assert_eq!(common, vec!['F', 'E', 'D', 'C', 'B', 'A']);
diff --git a/lib/src/repo.rs b/lib/src/repo.rs
index 1f74ee559..4db798e6b 100644
--- a/lib/src/repo.rs
+++ b/lib/src/repo.rs
@@ -851,14 +851,14 @@ impl MutableRepo {
         } else {
             let missing_commits = topo_order_reverse(
                 vec![head.clone()],
-                Box::new(|commit: &Commit| commit.id().clone()),
-                Box::new(|commit: &Commit| -> Vec<Commit> {
+                |commit: &Commit| commit.id().clone(),
+                |commit: &Commit| -> Vec<Commit> {
                     commit
                         .parents()
                         .into_iter()
                         .filter(|parent| !self.index().has_id(parent.id()))
                         .collect()
-                }),
+                },
             );
             for missing_commit in missing_commits.iter().rev() {
                 self.index.add_commit(missing_commit);
diff --git a/lib/src/rewrite.rs b/lib/src/rewrite.rs
index fbb540127..f199957ca 100644
--- a/lib/src/rewrite.rs
+++ b/lib/src/rewrite.rs
@@ -189,8 +189,8 @@ impl<'settings, 'repo> DescendantRebaser<'settings, 'repo> {
         // rewritten, make sure we rebase the rewritten parent first.
         let to_visit = dag_walk::topo_order_reverse(
             to_visit,
-            Box::new(|commit| commit.id().clone()),
-            Box::new(|commit| {
+            |commit| commit.id().clone(),
+            |commit| {
                 visited.insert(commit.id().clone());
                 let mut dependents = vec![];
                 for parent in commit.parents() {
@@ -206,7 +206,7 @@ impl<'settings, 'repo> DescendantRebaser<'settings, 'repo> {
                     }
                 }
                 dependents
-            }),
+            },
         );
 
         let new_commits = rewritten.values().flatten().cloned().collect();
diff --git a/src/commands/mod.rs b/src/commands/mod.rs
index 48039d484..a840591eb 100644
--- a/src/commands/mod.rs
+++ b/src/commands/mod.rs
@@ -1676,8 +1676,8 @@ fn cmd_obslog(ui: &mut Ui, command: &CommandHelper, args: &ObslogArgs) -> Result
 
     let commits = topo_order_reverse(
         vec![start_commit],
-        Box::new(|commit: &Commit| commit.id().clone()),
-        Box::new(|commit: &Commit| commit.predecessors()),
+        |commit: &Commit| commit.id().clone(),
+        |commit: &Commit| commit.predecessors(),
     );
     if !args.no_graph {
         let mut graph = get_graphlog(command.settings(), formatter.raw());
diff --git a/src/commands/operation.rs b/src/commands/operation.rs
index 96825435a..7c679757e 100644
--- a/src/commands/operation.rs
+++ b/src/commands/operation.rs
@@ -84,8 +84,8 @@ fn cmd_op_log(
     let default_node_symbol = graph.default_node_symbol().to_owned();
     for op in topo_order_reverse(
         vec![head_op],
-        Box::new(|op: &Operation| op.id().clone()),
-        Box::new(|op: &Operation| op.parents()),
+        |op: &Operation| op.id().clone(),
+        |op: &Operation| op.parents(),
     ) {
         let mut edges = vec![];
         for parent in op.parents() {