diff --git a/src/lib/queue.ts b/src/lib/queue.ts
index 73cd1df..f154eda 100644
--- a/src/lib/queue.ts
+++ b/src/lib/queue.ts
@@ -3,7 +3,7 @@ import { capture } from '@snapshot-labs/snapshot-sentry';
 import Cache from './cache';
 import { timeQueueProcess } from './metrics';
 
-const queues = new Set<Cache>();
+const queues = new Map<string, Cache>();
 const processingItems = new Map<string, Cache>();
 
 async function processItem(cacheable: Cache) {
@@ -17,13 +17,15 @@ async function processItem(cacheable: Cache) {
     capture(e, { id: cacheable.id });
     console.error(`[queue] Error while processing item`, e);
   } finally {
-    queues.delete(cacheable);
+    queues.delete(cacheable.id);
     processingItems.delete(cacheable.id);
   }
 }
 
 export function queue(cacheable: Cache) {
-  queues.add(cacheable);
+  if (!queues.has(cacheable.id)) {
+    queues.set(cacheable.id, cacheable);
+  }
 
   return queues.size;
 }
@@ -43,12 +45,11 @@ export function getProgress(id: string) {
 async function run() {
   try {
     console.log(`[queue] Poll queue (found ${queues.size} items)`);
-    queues.forEach(async cacheable => {
-      if (processingItems.has(cacheable.id)) {
+    queues.forEach(async (cacheable, id) => {
+      if (processingItems.has(id)) {
         console.log(
-          `[queue] Skip: ${cacheable} is currently being processed, progress: ${processingItems.get(
-            cacheable.id
-          )?.generationProgress}%`
+          `[queue] Skip: ${cacheable} is currently being processed, progress:
+          ${processingItems.get(id)?.generationProgress}%`
         );
         return;
       }