diff --git a/extensions/websockets-next/runtime/src/main/java/io/quarkus/websockets/next/runtime/Endpoints.java b/extensions/websockets-next/runtime/src/main/java/io/quarkus/websockets/next/runtime/Endpoints.java
index f3ca9d9247cd7..26bf46d6421a8 100644
--- a/extensions/websockets-next/runtime/src/main/java/io/quarkus/websockets/next/runtime/Endpoints.java
+++ b/extensions/websockets-next/runtime/src/main/java/io/quarkus/websockets/next/runtime/Endpoints.java
@@ -261,6 +261,9 @@ private static void handleFailure(UnhandledFailureStrategy strategy, Throwable c
     }
 
     private static void closeConnection(Throwable cause, WebSocketConnectionBase connection) {
+        if (connection.isClosed()) {
+            return;
+        }
         connection.close(CloseReason.INTERNAL_SERVER_ERROR).subscribe().with(
                 v -> LOG.debugf("Connection closed due to unhandled failure %s: %s", cause, connection),
                 t -> LOG.errorf("Unable to close connection [%s] due to unhandled failure [%s]: %s", connection.id(), cause,