diff --git a/core/src/test/java/io/questdb/client/test/cutlass/qwp/client/QwpQueryClientWalkTrackerTest.java b/core/src/test/java/io/questdb/client/test/cutlass/qwp/client/QwpQueryClientWalkTrackerTest.java
index 4a2544027..b4586893d 100644
--- a/core/src/test/java/io/questdb/client/test/cutlass/qwp/client/QwpQueryClientWalkTrackerTest.java
+++ b/core/src/test/java/io/questdb/client/test/cutlass/qwp/client/QwpQueryClientWalkTrackerTest.java
@@ -441,10 +441,15 @@ public void testWalk_TransportFailureContinuesWalk() throws Exception {
         // First port has no server (TCP refused); second is reachable.
         // WalkTracker must classify the first as TransportError and bind
         // the second on the same walk (no fall-through reset needed yet).
-        int portDead = TestPorts.findUnusedPort();
         try (TestWebSocketServer ok = new TestWebSocketServer(NOOP_HANDLER)) {
             ok.setSendServerInfo(true);
             int portOk = ok.getPort();
+            // Probe the dead port only while ok's listener holds portOk: the
+            // kernel never hands out a port a live listener owns, so portDead
+            // cannot collide with portOk. Probing first lets the server's own
+            // bind(0) receive the just-released probe port, and the duplicate
+            // addr entry then fails config validation.
+            int portDead = TestPorts.findUnusedPort();
             ok.start();
             Assert.assertTrue(ok.awaitStart(5, TimeUnit.SECONDS));