diff --git a/src/ledger/src/data_model/effects.rs b/src/ledger/src/data_model/effects.rs
index e086a2034..494edbef2 100644
--- a/src/ledger/src/data_model/effects.rs
+++ b/src/ledger/src/data_model/effects.rs
@@ -287,7 +287,7 @@ impl TxnEffect {
 
         // (1), within this transaction
         //let v = vec![];
-        let iss_nums = self.new_issuance_nums.entry(code).or_insert_with(Vec::new);
+        let iss_nums = self.new_issuance_nums.entry(code).or_default();
 
         if let Some(last_num) = iss_nums.last() {
             if seq_num <= *last_num {
diff --git a/src/ledger/src/staking/mod.rs b/src/ledger/src/staking/mod.rs
index 7a42430b2..de471b8d2 100644
--- a/src/ledger/src/staking/mod.rs
+++ b/src/ledger/src/staking/mod.rs
@@ -809,7 +809,7 @@ impl Staking {
         self.delegation_info
             .end_height_map
             .entry(end_height)
-            .or_insert_with(BTreeSet::new)
+            .or_default()
             .insert(owner);
 
         // There should be no failure here !!
@@ -903,7 +903,7 @@ impl Staking {
             self.delegation_info
                 .end_height_map
                 .entry(h + CFG.checkpoint.unbond_block_cnt)
-                .or_insert_with(BTreeSet::new)
+                .or_default()
                 .insert(*addr);
         }
 
@@ -995,7 +995,7 @@ impl Staking {
         self.delegation_info
             .end_height_map
             .entry(h + CFG.checkpoint.unbond_block_cnt)
-            .or_insert_with(BTreeSet::new)
+            .or_default()
             .insert(pu.new_delegator_id);
 
         // update delegator entries for pu target_validator
@@ -1078,7 +1078,7 @@ impl Staking {
             self.delegation_info
                 .end_height_map
                 .entry(end_height)
-                .or_insert_with(BTreeSet::new)
+                .or_default()
                 .insert(addr.to_owned());
             Ok(())
         } else {