diff --git a/app/src/main/kotlin/com/tutpro/baresip/Config.kt b/app/src/main/kotlin/com/tutpro/baresip/Config.kt
index 8ba61aa9..6db20ec3 100644
--- a/app/src/main/kotlin/com/tutpro/baresip/Config.kt
+++ b/app/src/main/kotlin/com/tutpro/baresip/Config.kt
@@ -45,6 +45,8 @@ object Config {
         val sipListen = previousVariable("sip_listen")
         if (sipListen != "")
             config = "${config}sip_listen $sipListen\n"
+        else
+            config = "${config}sip_listen 0.0.0.0:5060\n"
 
         val addressFamily = previousVariable("net_af")
         if (addressFamily != "") {
diff --git a/app/src/main/kotlin/com/tutpro/baresip/ConfigActivity.kt b/app/src/main/kotlin/com/tutpro/baresip/ConfigActivity.kt
index 0e131dfb..0edf1016 100644
--- a/app/src/main/kotlin/com/tutpro/baresip/ConfigActivity.kt
+++ b/app/src/main/kotlin/com/tutpro/baresip/ConfigActivity.kt
@@ -592,7 +592,10 @@ class ConfigActivity : AppCompatActivity() {
                                 "${getString(R.string.invalid_listen_address)}: $listenAddr")
                         return false
                     }
-                    Config.replaceVariable("sip_listen", listenAddr)
+                    if (listenAddr != "")
+                        Config.replaceVariable("sip_listen", listenAddr)
+                    else
+                         Config.removeVariable("sip_listen")
                     save = true
                     restart = true
                 }