diff --git a/src/app-bridge/app-bridge.ts b/src/app-bridge/app-bridge.ts
index da18d45..55d15ac 100644
--- a/src/app-bridge/app-bridge.ts
+++ b/src/app-bridge/app-bridge.ts
@@ -95,6 +95,12 @@ export class AppBridge {
       console.warn("document.referrer is empty");
     }
 
+    if (!this.combinedOptions.targetDomain) {
+      console.error(
+        "No domain set, ensure ?domain param in iframe exist or provide in AppBridge constructor"
+      );
+    }
+
     this.setInitialState();
     this.listenOnMessages();
   }
diff --git a/src/app-bridge/index.ts b/src/app-bridge/index.ts
index 654bd60..29d16b9 100644
--- a/src/app-bridge/index.ts
+++ b/src/app-bridge/index.ts
@@ -9,5 +9,6 @@ export * from "./types";
 /**
  * @deprecated use new AppBridge(), createApp will be removed
  */
-export const createApp = (targetDomain?: string) => new AppBridge({ targetDomain });
+export const createApp = (targetDomain?: string) =>
+  new AppBridge(targetDomain ? { targetDomain } : undefined);
 export default createApp;