diff --git a/src/mixins/lit-localize-mixin.ts b/src/mixins/lit-localize-mixin.ts
index fdd9cd7a48..3692e98e81 100644
--- a/src/mixins/lit-localize-mixin.ts
+++ b/src/mixins/lit-localize-mixin.ts
@@ -11,6 +11,8 @@ import {
   LocalizeMixin,
 } from "./localize-base-mixin";
 
+const empty = () => "";
+
 export const HassLocalizeLitMixin = <T extends LitElement>(
   superClass: Constructor<T>
 ): Constructor<T & LocalizeMixin> =>
@@ -26,6 +28,12 @@ export const HassLocalizeLitMixin = <T extends LitElement>(
       };
     }
 
+    constructor() {
+      super();
+      // This will prevent undefined errors if called before connected to DOM.
+      this.localize = empty;
+    }
+
     public connectedCallback(): void {
       super.connectedCallback();