diff --git a/common/lkt.js b/common/lkt.js
index 5b7a0bd78aa88f53274f7515d31ad298daacabab..283a4683a90edbd9e26cca3d70f0fec6bcc9c019 100644
--- a/common/lkt.js
+++ b/common/lkt.js
@@ -292,8 +292,9 @@ class LktClient {
                         else{
                             karaList.splice(-1);
                         }
-                        if(karaList[0] == "OK") {
-                            client.close();
+                        if(karaList[0]=="OK"){
+			    client.close();
+			    return null;
                         }
                         karaList.forEach(kara => {
                             matches = reg.exec(kara);