diff --git a/CHANGELOG.md b/CHANGELOG.md
index e1b8ffb..1e62772 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -23,6 +23,8 @@ TODO
 
 - Fixed mangled output with mode SHOW_SCMP_ONLY
   [#31](https://github.com/netsec-ethz/scion-java-multiping/pull/31)
+- Fixed occurrence of ISD=0 / "AS not listed"
+  [#32](https://github.com/netsec-ethz/scion-java-multiping/pull/32)
 
 ## [0.6.1] - 2025-12-12
 
diff --git a/src/main/java/org/scion/multiping/PingAll.java b/src/main/java/org/scion/multiping/PingAll.java
index 654cae9..3d4a45e 100644
--- a/src/main/java/org/scion/multiping/PingAll.java
+++ b/src/main/java/org/scion/multiping/PingAll.java
@@ -436,7 +436,6 @@ public void onException(Throwable t) {
     for (Scmp.TimedMessage tm : messages.values()) {
       Scmp.TracerouteMessage msg = (Scmp.TracerouteMessage) tm;
       summary.checkTotalMax(msg.getIsdAs(), msg);
-      seenAs.add(msg.getIsdAs());
 
       if (msg.isTimedOut()) {
         summary.incPathTimeout();
@@ -446,6 +445,7 @@ public void onException(Throwable t) {
         continue;
       }
 
+      seenAs.add(msg.getIsdAs());
       summary.incPathSuccess();
 
       if (best == null || msg.getNanoSeconds() < best.getNanoSeconds()) {