diff --git a/backend/src/api/common.ts b/backend/src/api/common.ts
index 13fc86147..f3d3e43b5 100644
--- a/backend/src/api/common.ts
+++ b/backend/src/api/common.ts
@@ -80,8 +80,8 @@ export class Common {
     return arr;
   }
 
-  static findRbfTransactions(added: MempoolTransactionExtended[], deleted: MempoolTransactionExtended[], forceScalable = false): { [txid: string]: MempoolTransactionExtended[] } {
-    const matches: { [txid: string]: MempoolTransactionExtended[] } = {};
+  static findRbfTransactions(added: MempoolTransactionExtended[], deleted: MempoolTransactionExtended[], forceScalable = false): { [txid: string]: { replaced: MempoolTransactionExtended[], replacedBy: TransactionExtended }} {
+    const matches: { [txid: string]: { replaced: MempoolTransactionExtended[], replacedBy: TransactionExtended }} = {};
 
     // For small N, a naive nested loop is extremely fast, but it doesn't scale
     if (added.length < 1000 && deleted.length < 50 && !forceScalable) {
@@ -96,7 +96,7 @@ export class Common {
               addedTx.vin.some((vin) => vin.txid === deletedVin.txid && vin.vout === deletedVin.vout));
             });
         if (foundMatches?.length) {
-          matches[addedTx.txid] = [...new Set(foundMatches)];
+          matches[addedTx.txid] = { replaced: [...new Set(foundMatches)], replacedBy: addedTx };
         }
       });
     } else {
@@ -124,7 +124,7 @@ export class Common {
             foundMatches.add(deletedTx);
           }
           if (foundMatches.size) {
-            matches[addedTx.txid] = [...foundMatches];
+            matches[addedTx.txid] = { replaced: [...foundMatches], replacedBy: addedTx };
           }
         }
       }
@@ -139,17 +139,17 @@ export class Common {
       const replaced: Set<MempoolTransactionExtended> = new Set();
       for (let i = 0; i < tx.vin.length; i++) {
         const vin = tx.vin[i];
-        const match = spendMap.get(`${vin.txid}:${vin.vout}`);
+        const key = `${vin.txid}:${vin.vout}`;
+        const match = spendMap.get(key);
         if (match && match.txid !== tx.txid) {
           replaced.add(match);
           // remove this tx from the spendMap
           // prevents the same tx being replaced more than once
           for (const replacedVin of match.vin) {
-            const key = `${replacedVin.txid}:${replacedVin.vout}`;
-            spendMap.delete(key);
+            const replacedKey = `${replacedVin.txid}:${replacedVin.vout}`;
+            spendMap.delete(replacedKey);
           }
         }
-        const key = `${vin.txid}:${vin.vout}`;
         spendMap.delete(key);
       }
       if (replaced.size) {
diff --git a/backend/src/api/mempool.ts b/backend/src/api/mempool.ts
index 1f55179fb..1442b05fa 100644
--- a/backend/src/api/mempool.ts
+++ b/backend/src/api/mempool.ts
@@ -19,12 +19,13 @@ class Mempool {
   private mempoolCache: { [txId: string]: MempoolTransactionExtended } = {};
   private mempoolCandidates: { [txid: string ]: boolean } = {};
   private spendMap = new Map<string, MempoolTransactionExtended>();
+  private recentlyDeleted: MempoolTransactionExtended[][] = []; // buffer of transactions deleted in recent mempool updates
   private mempoolInfo: IBitcoinApi.MempoolInfo = { loaded: false, size: 0, bytes: 0, usage: 0, total_fee: 0,
                                                     maxmempool: 300000000, mempoolminfee: Common.isLiquid() ? 0.00000100 : 0.00001000, minrelaytxfee: Common.isLiquid() ? 0.00000100 : 0.00001000 };
   private mempoolChangedCallback: ((newMempool: {[txId: string]: MempoolTransactionExtended; }, newTransactions: MempoolTransactionExtended[],
-    deletedTransactions: MempoolTransactionExtended[], accelerationDelta: string[]) => void) | undefined;
+    deletedTransactions: MempoolTransactionExtended[][], accelerationDelta: string[]) => void) | undefined;
   private $asyncMempoolChangedCallback: ((newMempool: {[txId: string]: MempoolTransactionExtended; }, mempoolSize: number, newTransactions: MempoolTransactionExtended[],
-    deletedTransactions: MempoolTransactionExtended[], accelerationDelta: string[], candidates?: GbtCandidates) => Promise<void>) | undefined;
+    deletedTransactions: MempoolTransactionExtended[][], accelerationDelta: string[], candidates?: GbtCandidates) => Promise<void>) | undefined;
 
   private accelerations: { [txId: string]: Acceleration } = {};
   private accelerationPositions: { [txid: string]: { poolId: number, pool: string, block: number, vsize: number }[] } = {};
@@ -74,12 +75,12 @@ class Mempool {
   }
 
   public setMempoolChangedCallback(fn: (newMempool: { [txId: string]: MempoolTransactionExtended; },
-    newTransactions: MempoolTransactionExtended[], deletedTransactions: MempoolTransactionExtended[], accelerationDelta: string[]) => void): void {
+    newTransactions: MempoolTransactionExtended[], deletedTransactions: MempoolTransactionExtended[][], accelerationDelta: string[]) => void): void {
     this.mempoolChangedCallback = fn;
   }
 
   public setAsyncMempoolChangedCallback(fn: (newMempool: { [txId: string]: MempoolTransactionExtended; }, mempoolSize: number,
-    newTransactions: MempoolTransactionExtended[], deletedTransactions: MempoolTransactionExtended[], accelerationDelta: string[],
+    newTransactions: MempoolTransactionExtended[], deletedTransactions: MempoolTransactionExtended[][], accelerationDelta: string[],
     candidates?: GbtCandidates) => Promise<void>): void {
     this.$asyncMempoolChangedCallback = fn;
   }
@@ -362,12 +363,15 @@ class Mempool {
 
     const candidatesChanged = candidates?.added?.length || candidates?.removed?.length;
 
-    if (this.mempoolChangedCallback && (hasChange || deletedTransactions.length)) {
-      this.mempoolChangedCallback(this.mempoolCache, newTransactions, deletedTransactions, accelerationDelta);
+    this.recentlyDeleted.unshift(deletedTransactions);
+    this.recentlyDeleted.length = Math.min(this.recentlyDeleted.length, 10); // truncate to the last 10 mempool updates
+
+    if (this.mempoolChangedCallback && (hasChange || newTransactions.length || deletedTransactions.length)) {
+      this.mempoolChangedCallback(this.mempoolCache, newTransactions, this.recentlyDeleted, accelerationDelta);
     }
-    if (this.$asyncMempoolChangedCallback && (hasChange || deletedTransactions.length || candidatesChanged)) {
+    if (this.$asyncMempoolChangedCallback && (hasChange || newTransactions.length || deletedTransactions.length || candidatesChanged)) {
       this.updateTimerProgress(timer, 'running async mempool callback');
-      await this.$asyncMempoolChangedCallback(this.mempoolCache, newMempoolSize, newTransactions, deletedTransactions, accelerationDelta, candidates);
+      await this.$asyncMempoolChangedCallback(this.mempoolCache, newMempoolSize, newTransactions, this.recentlyDeleted, accelerationDelta, candidates);
       this.updateTimerProgress(timer, 'completed async mempool callback');
     }
 
@@ -541,16 +545,7 @@ class Mempool {
     }
   }
 
-  public handleRbfTransactions(rbfTransactions: { [txid: string]: MempoolTransactionExtended[]; }): void {
-    for (const rbfTransaction in rbfTransactions) {
-      if (this.mempoolCache[rbfTransaction] && rbfTransactions[rbfTransaction]?.length) {
-        // Store replaced transactions
-        rbfCache.add(rbfTransactions[rbfTransaction], this.mempoolCache[rbfTransaction]);
-      }
-    }
-  }
-
-  public handleMinedRbfTransactions(rbfTransactions: { [txid: string]: { replaced: MempoolTransactionExtended[], replacedBy: TransactionExtended }}): void {
+  public handleRbfTransactions(rbfTransactions: { [txid: string]: { replaced: MempoolTransactionExtended[], replacedBy: TransactionExtended }}): void {
     for (const rbfTransaction in rbfTransactions) {
       if (rbfTransactions[rbfTransaction].replacedBy && rbfTransactions[rbfTransaction]?.replaced?.length) {
         // Store replaced transactions
diff --git a/backend/src/api/websocket-handler.ts b/backend/src/api/websocket-handler.ts
index 79a783f88..2a047472e 100644
--- a/backend/src/api/websocket-handler.ts
+++ b/backend/src/api/websocket-handler.ts
@@ -520,8 +520,17 @@ class WebsocketHandler {
     }
   }
 
+  /**
+   *
+   * @param newMempool
+   * @param mempoolSize
+   * @param newTransactions  array of transactions added this mempool update.
+   * @param recentlyDeletedTransactions array of arrays of transactions removed in the last N mempool updates, most recent first.
+   * @param accelerationDelta
+   * @param candidates
+   */
   async $handleMempoolChange(newMempool: { [txid: string]: MempoolTransactionExtended }, mempoolSize: number,
-    newTransactions: MempoolTransactionExtended[], deletedTransactions: MempoolTransactionExtended[], accelerationDelta: string[],
+    newTransactions: MempoolTransactionExtended[], recentlyDeletedTransactions: MempoolTransactionExtended[][], accelerationDelta: string[],
     candidates?: GbtCandidates): Promise<void> {
     if (!this.webSocketServers.length) {
       throw new Error('No WebSocket.Server have been set');
@@ -529,6 +538,8 @@ class WebsocketHandler {
 
     this.printLogs();
 
+    const deletedTransactions = recentlyDeletedTransactions.length ? recentlyDeletedTransactions[0] : [];
+
     const transactionIds = (memPool.limitGBT && candidates) ? Object.keys(candidates?.txs || {}) : Object.keys(newMempool);
     let added = newTransactions;
     let removed = deletedTransactions;
@@ -547,7 +558,7 @@ class WebsocketHandler {
     const mBlockDeltas = mempoolBlocks.getMempoolBlockDeltas();
     const mempoolInfo = memPool.getMempoolInfo();
     const vBytesPerSecond = memPool.getVBytesPerSecond();
-    const rbfTransactions = Common.findRbfTransactions(newTransactions, deletedTransactions);
+    const rbfTransactions = Common.findRbfTransactions(newTransactions, recentlyDeletedTransactions.flat());
     const da = difficultyAdjustment.getDifficultyAdjustment();
     const accelerations = memPool.getAccelerations();
     memPool.handleRbfTransactions(rbfTransactions);
@@ -578,7 +589,7 @@ class WebsocketHandler {
     const replacedTransactions: { replaced: string, by: TransactionExtended }[] = [];
     for (const tx of newTransactions) {
       if (rbfTransactions[tx.txid]) {
-        for (const replaced of rbfTransactions[tx.txid]) {
+        for (const replaced of rbfTransactions[tx.txid].replaced) {
           replacedTransactions.push({ replaced: replaced.txid, by: tx });
         }
       }
@@ -947,7 +958,7 @@ class WebsocketHandler {
     await accelerationRepository.$indexAccelerationsForBlock(block, accelerations, structuredClone(transactions));
 
     const rbfTransactions = Common.findMinedRbfTransactions(transactions, memPool.getSpendMap());
-    memPool.handleMinedRbfTransactions(rbfTransactions);
+    memPool.handleRbfTransactions(rbfTransactions);
     memPool.removeFromSpendMap(transactions);
 
     if (config.MEMPOOL.AUDIT && memPool.isInSync()) {