diff --git a/src/panels/config/helpers/forms/ha-timer-form.ts b/src/panels/config/helpers/forms/ha-timer-form.ts
index 800fefcc27..32e1f25e7a 100644
--- a/src/panels/config/helpers/forms/ha-timer-form.ts
+++ b/src/panels/config/helpers/forms/ha-timer-form.ts
@@ -25,7 +25,7 @@ class HaTimerForm extends LitElement {
     if (item) {
       this._name = item.name || "";
       this._icon = item.icon || "";
-      this._duration = item.duration || "";
+      this._duration = item.duration || "00:00:00";
     } else {
       this._name = "";
       this._icon = "";