diff --git a/app/src/main/kotlin/com/tutpro/baresip/AccountActivity.kt b/app/src/main/kotlin/com/tutpro/baresip/AccountActivity.kt
index 41f5a667..0dee4d63 100644
--- a/app/src/main/kotlin/com/tutpro/baresip/AccountActivity.kt
+++ b/app/src/main/kotlin/com/tutpro/baresip/AccountActivity.kt
@@ -527,7 +527,7 @@ class AccountActivity : AppCompatActivity() {
                 if (newConfiguredRegInt < 60 || newConfiguredRegInt > 3600) {
                     Utils.alertView(
                         this, getString(R.string.notice),
-                        String.format(getString(R.string.invalid_reg_int), newConfiguredRegInt)
+                        String.format(getString(R.string.invalid_reg_int), "$newConfiguredRegInt")
                     )
                     return false
                 }