diff --git a/lib/src/operation.rs b/lib/src/operation.rs
index 6d7d763cd..990090d68 100644
--- a/lib/src/operation.rs
+++ b/lib/src/operation.rs
@@ -19,8 +19,8 @@ use std::hash::{Hash, Hasher};
 use std::sync::Arc;
 
 use crate::backend::CommitId;
-use crate::op_store;
 use crate::op_store::{OpStore, OperationId, ViewId};
+use crate::{dag_walk, op_store};
 
 #[derive(Clone)]
 pub struct Operation {
@@ -165,3 +165,34 @@ impl View {
         &self.data.head_ids
     }
 }
+
+#[derive(Clone, Debug, Eq, Hash, PartialEq)]
+struct OperationByEndTime(Operation);
+
+impl Ord for OperationByEndTime {
+    fn cmp(&self, other: &Self) -> Ordering {
+        let self_end_time = &self.0.store_operation().metadata.end_time;
+        let other_end_time = &other.0.store_operation().metadata.end_time;
+        self_end_time
+            .cmp(other_end_time)
+            .then_with(|| self.0.cmp(&other.0)) // to comply with Eq
+    }
+}
+
+impl PartialOrd for OperationByEndTime {
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+}
+
+/// Walks `head_op` and its ancestors in reverse topological order.
+pub fn walk_ancestors(head_op: &Operation) -> impl Iterator<Item = Operation> {
+    // Lazily load operations based on timestamp-based heuristic. This works so long
+    // as the operation history is mostly linear.
+    dag_walk::topo_order_reverse_lazy(
+        vec![OperationByEndTime(head_op.clone())],
+        |OperationByEndTime(op)| op.id().clone(),
+        |OperationByEndTime(op)| op.parents().into_iter().map(OperationByEndTime),
+    )
+    .map(|OperationByEndTime(op)| op)
+}
diff --git a/src/commands/operation.rs b/src/commands/operation.rs
index 7c679757e..49fe8dd19 100644
--- a/src/commands/operation.rs
+++ b/src/commands/operation.rs
@@ -1,6 +1,5 @@
 use clap::Subcommand;
-use jujutsu_lib::dag_walk::topo_order_reverse;
-use jujutsu_lib::operation::Operation;
+use jujutsu_lib::operation;
 
 use crate::cli_util::{user_error, CommandError, CommandHelper, LogContentFormat};
 use crate::graphlog::{get_graphlog, Edge};
@@ -82,11 +81,7 @@ fn cmd_op_log(
     let formatter = formatter.as_mut();
     let mut graph = get_graphlog(command.settings(), formatter.raw());
     let default_node_symbol = graph.default_node_symbol().to_owned();
-    for op in topo_order_reverse(
-        vec![head_op],
-        |op: &Operation| op.id().clone(),
-        |op: &Operation| op.parents(),
-    ) {
+    for op in operation::walk_ancestors(&head_op) {
         let mut edges = vec![];
         for parent in op.parents() {
             edges.push(Edge::direct(parent.id().clone()));