diff --git a/packages/node/src/indexer/indexer.manager.ts b/packages/node/src/indexer/indexer.manager.ts
index fa6f7a2d40..dde11c5be7 100644
--- a/packages/node/src/indexer/indexer.manager.ts
+++ b/packages/node/src/indexer/indexer.manager.ts
@@ -112,14 +112,12 @@ export class IndexerManager extends BaseIndexerManager<
       const groupedEvents = events.reduce(
         (acc, evt, idx) => {
           if (evt.phase.isInitialization) {
-            acc.init ??= [];
             acc.init.push(evt);
           } else if (evt.phase.isFinalization) {
-            acc.finalize ??= [];
             acc.finalize.push(evt);
           } else if (evt.extrinsic?.idx) {
             const idx = evt.extrinsic.idx;
-            acc[idx] = acc[idx] || [];
+            acc[idx] ??= [];
             acc[idx].push(evt);
           } else {
             logger.warn(
@@ -128,11 +126,14 @@ export class IndexerManager extends BaseIndexerManager<
           }
           return acc;
         },
-        {} as Record<number | 'init' | 'finalize', SubstrateEvent[]>,
+        { init: [], finalize: [] } as Record<
+          number | 'init' | 'finalize',
+          SubstrateEvent[]
+        >,
       );
 
       // Run initialization events
-      for (const event of groupedEvents.init ?? []) {
+      for (const event of groupedEvents.init) {
         await this.indexEvent(event, dataSources, getVM);
       }
 
@@ -150,7 +151,7 @@ export class IndexerManager extends BaseIndexerManager<
       }
 
       // Run finalization events
-      for (const event of groupedEvents.finalize ?? []) {
+      for (const event of groupedEvents.finalize) {
         await this.indexEvent(event, dataSources, getVM);
       }
     } else {
diff --git a/packages/node/src/utils/substrate.ts b/packages/node/src/utils/substrate.ts
index a0e563f707..882a41d027 100644
--- a/packages/node/src/utils/substrate.ts
+++ b/packages/node/src/utils/substrate.ts
@@ -121,9 +121,7 @@ function groupEventsByExtrinsic(
       if (extrinsicIdx === undefined) {
         return acc;
       }
-      if (!acc[extrinsicIdx]) {
-        acc[extrinsicIdx] = [];
-      }
+      acc[extrinsicIdx] ??= [];
       acc[extrinsicIdx].push(event);
       return acc;
     },