diff --git a/web/src/main/java/de/cotto/lndmanagej/controller/PaymentStatusStream.java b/web/src/main/java/de/cotto/lndmanagej/controller/PaymentStatusStream.java
index 8ea887d1..c4192dd6 100644
--- a/web/src/main/java/de/cotto/lndmanagej/controller/PaymentStatusStream.java
+++ b/web/src/main/java/de/cotto/lndmanagej/controller/PaymentStatusStream.java
@@ -7,6 +7,7 @@ import org.springframework.stereotype.Component;
 import org.springframework.web.servlet.mvc.method.annotation.StreamingResponseBody;
 
 import java.nio.charset.StandardCharsets;
+import java.util.ArrayList;
 import java.util.List;
 
 @Component
@@ -21,7 +22,7 @@ public class PaymentStatusStream {
         return response -> {
             int seenMessages = 0;
             do {
-                List<InstantWithString> messages = paymentStatus.getMessages();
+                List<InstantWithString> messages = new ArrayList<>(paymentStatus.getMessages());
                 int oldMessages = seenMessages;
                 seenMessages = messages.size();
                 for (int i = oldMessages; i < messages.size(); i++) {