diff --git a/backend/src/api/websocket-handler.ts b/backend/src/api/websocket-handler.ts
index 57ea4f32a..c9a7f1789 100644
--- a/backend/src/api/websocket-handler.ts
+++ b/backend/src/api/websocket-handler.ts
@@ -136,7 +136,7 @@ class WebsocketHandler {
         const foundTransactions: TransactionExtended[] = [];
 
         newTransactions.forEach((tx) => {
-          const someVin = tx.vin.some((vin) => vin.prevout.scriptpubkey_address === client['track-address']);
+          const someVin = tx.vin.some((vin) => vin.prevout && vin.prevout.scriptpubkey_address === client['track-address']);
           if (someVin) {
             foundTransactions.push(tx);
             return;
@@ -185,7 +185,7 @@ class WebsocketHandler {
         const foundTransactions: TransactionExtended[] = [];
 
         transactions.forEach((tx) => {
-          if (tx.vin && tx.vin.some((vin) => vin.prevout.scriptpubkey_address === client['track-address'])) {
+          if (tx.vin && tx.vin.some((vin) => vin.prevout && vin.prevout.scriptpubkey_address === client['track-address'])) {
             foundTransactions.push(tx);
             return;
           }
diff --git a/backend/src/interfaces.ts b/backend/src/interfaces.ts
index 95e28adeb..43d418846 100644
--- a/backend/src/interfaces.ts
+++ b/backend/src/interfaces.ts
@@ -47,7 +47,7 @@ export interface Prevout {
 export interface Vin {
   txid: string;
   vout: number;
-  prevout: Prevout;
+  prevout?: Prevout;
   scriptsig: string;
   scriptsig_asm: string;
   inner_redeemscript_asm?: string;