diff --git a/backend/src/api/websocket-handler.ts b/backend/src/api/websocket-handler.ts
index cffbea346..599c068a6 100644
--- a/backend/src/api/websocket-handler.ts
+++ b/backend/src/api/websocket-handler.ts
@@ -19,6 +19,7 @@ import feeApi from './fee-api';
 import BlocksAuditsRepository from '../repositories/BlocksAuditsRepository';
 import BlocksSummariesRepository from '../repositories/BlocksSummariesRepository';
 import Audit from './audit';
+import { deepClone } from '../utils/clone';
 
 class WebsocketHandler {
   private wss: WebSocket.Server | undefined;
@@ -421,7 +422,7 @@ class WebsocketHandler {
     let projectedBlocks;
     // template calculation functions have mempool side effects, so calculate audits using
     // a cloned copy of the mempool if we're running a different algorithm for mempool updates
-    const auditMempool = (config.MEMPOOL.ADVANCED_GBT_AUDIT === config.MEMPOOL.ADVANCED_GBT_MEMPOOL) ? _memPool : JSON.parse(JSON.stringify(_memPool));
+    const auditMempool = (config.MEMPOOL.ADVANCED_GBT_AUDIT === config.MEMPOOL.ADVANCED_GBT_MEMPOOL) ? _memPool : deepClone(_memPool);
     if (config.MEMPOOL.ADVANCED_GBT_AUDIT) {
       projectedBlocks = await mempoolBlocks.makeBlockTemplates(auditMempool, false);
     } else {
diff --git a/backend/src/utils/clone.ts b/backend/src/utils/clone.ts
new file mode 100644
index 000000000..38e36096f
--- /dev/null
+++ b/backend/src/utils/clone.ts
@@ -0,0 +1,14 @@
+// simple recursive deep clone for literal-type objects
+// does not preserve Dates, Maps, Sets etc
+// does not support recursive objects
+// properties deeper than maxDepth will be shallow cloned
+export function deepClone(obj: any, maxDepth: number = 50, depth: number = 0): any {
+  let cloned = obj;
+  if (depth < maxDepth && typeof obj === 'object') {
+    cloned = Array.isArray(obj) ? [] : {};
+    for (const key in obj) {
+      cloned[key] = deepClone(obj[key], maxDepth, depth + 1);
+    }
+  }
+  return cloned;
+}
\ No newline at end of file