diff --git a/rs/nns/governance/src/governance.rs b/rs/nns/governance/src/governance.rs
index 0e85ed55a115..895cadd0e859 100644
--- a/rs/nns/governance/src/governance.rs
+++ b/rs/nns/governance/src/governance.rs
@@ -95,6 +95,7 @@ use ic_nns_constants::{
     LIFELINE_CANISTER_ID, REGISTRY_CANISTER_ID, ROOT_CANISTER_ID, SNS_WASM_CANISTER_ID,
     SUBNET_RENTAL_CANISTER_ID,
 };
+use ic_nns_governance_api::pb::v1::list_neurons::NeuronSubaccount;
 use ic_nns_governance_api::{
     pb::v1::{
         self as api,
@@ -2277,17 +2278,21 @@ impl Governance {
             BTreeSet::new()
         };
 
-        let mut neurons_by_subaccount: BTreeSet<NeuronId> = neuron_subaccounts
-            .unwrap_or_default()
-            .iter()
-            .flat_map(|neuron_subaccount| {
-                Self::bytes_to_subaccount(&neuron_subaccount.subaccount)
-                    .ok()
-                    .and_then(|subaccount| {
-                        self.neuron_store.get_neuron_id_for_subaccount(subaccount)
+        let neurons_by_subaccount: BTreeSet<NeuronId> = neuron_subaccounts
+            .as_ref()
+            .map(|subaccounts| {
+                subaccounts
+                    .iter()
+                    .flat_map(|neuron_subaccount| {
+                        Self::bytes_to_subaccount(&neuron_subaccount.subaccount)
+                            .ok()
+                            .and_then(|subaccount| {
+                                self.neuron_store.get_neuron_id_for_subaccount(subaccount)
+                            })
                     })
+                    .collect()
             })
-            .collect();
+            .unwrap_or_default();
 
         // Concatenate (explicit and implicit)-ly included neurons.
         let mut requested_neuron_ids: BTreeSet<NeuronId> =