diff --git a/container/src/LuigiContainer.svelte b/container/src/LuigiContainer.svelte
index daaa608b9f..23db2af73c 100644
--- a/container/src/LuigiContainer.svelte
+++ b/container/src/LuigiContainer.svelte
@@ -145,7 +145,7 @@
         }
       };
 
-      thisComponent.closeAlert = (id: string, dismissKey: string) => {
+      thisComponent.closeAlert = (id: string, dismissKey?: string) => {
         ContainerAPI.closeAlert(id, dismissKey, iframeHandle);
       };
 
diff --git a/container/src/api/container-api.ts b/container/src/api/container-api.ts
index 8e38801cb6..5e48a5cc5a 100644
--- a/container/src/api/container-api.ts
+++ b/container/src/api/container-api.ts
@@ -95,11 +95,12 @@ export class ContainerAPIFunctions {
   /**
    * Send a message to the microfrontend notifying the alert has been closed
    * @param id the id of the alert being closed
-   * @param dismissKey the dismiss key being sent if any
-   * @param iframeHandle the handle of the iframe to send the message to
+   * @param dismissKey the dismiss key being sent if any (optional)
+   * @param iframeHandle the handle of the iframe to send the message to (optional)
    */
-  closeAlert(id: string, dismissKey: string, iframeHandle: IframeHandle) {
-    containerService.sendCustomMessageToIframe(iframeHandle, { id, dismissKey }, LuigiInternalMessageID.ALERT_CLOSED);
+  closeAlert(id: string, dismissKey?: string, iframeHandle?: IframeHandle) {
+    const message = dismissKey ? { id, dismissKey } : { id };
+    containerService.sendCustomMessageToIframe(iframeHandle, message, LuigiInternalMessageID.ALERT_CLOSED);
   }
 }
 
diff --git a/container/src/services/container.service.ts b/container/src/services/container.service.ts
index 17d90b1869..84852d1ed4 100644
--- a/container/src/services/container.service.ts
+++ b/container/src/services/container.service.ts
@@ -24,7 +24,7 @@ export class ContainerService {
   sendCustomMessageToIframe(iframeHandle: IframeHandle, msg: object, msgName?: string) {
     const messageName = msgName || 'custom';
 
-    if (iframeHandle.iframe.contentWindow) {
+    if (iframeHandle?.iframe?.contentWindow) {
       const iframeUrl = new URL(iframeHandle.iframe.src);
       if (messageName === 'custom') {
         iframeHandle.iframe.contentWindow.postMessage({ msg: messageName, data: msg }, iframeUrl.origin);
diff --git a/container/test/api/container-api.spec.ts b/container/test/api/container-api.spec.ts
index e317f9582d..681c14b474 100644
--- a/container/test/api/container-api.spec.ts
+++ b/container/test/api/container-api.spec.ts
@@ -218,6 +218,20 @@ describe('Container Service', () => {
 
       expect(spy).toHaveBeenCalledWith(iframeHandle, { id, dismissKey }, LuigiInternalMessageID.ALERT_CLOSED);
     });
+
+    it('internal method properly called if no dismisskey', () => {
+      // mock and spy
+      const id = 'some-id';
+      const iframeHandle = {
+        data: 'test'
+      } as unknown as IframeHandle;
+      containerService.sendCustomMessageToIframe = jest.fn();
+      const spy = jest.spyOn(containerService, 'sendCustomMessageToIframe');
+
+      containerAPI.closeAlert(id, undefined, iframeHandle);
+
+      expect(spy).toHaveBeenCalledWith(iframeHandle, { id }, LuigiInternalMessageID.ALERT_CLOSED);
+    });
   });
 
   describe('sendCustomMessage', () => {
diff --git a/container/typings/LuigiContainer.svelte.d.ts b/container/typings/LuigiContainer.svelte.d.ts
index 34fa36e488..16073f7019 100644
--- a/container/typings/LuigiContainer.svelte.d.ts
+++ b/container/typings/LuigiContainer.svelte.d.ts
@@ -246,12 +246,12 @@ export default class LuigiContainer extends HTMLElement {
   /**
    * A function that notifies the microfrontend that the opened alert has been closed.
    * @param id the id of the opened alert
-   * @param dismissKey the key specifying which dismiss link was clicked on the alert message
+   * @param dismissKey the key specifying which dismiss link was clicked on the alert message (optional)
    * @example
    * containerElement.closeAlert('my-alert-id', 'my-dismiss-key')
    * @since 1.0.0
    */
-  closeAlert(id: string, dismissKey: string): void;
+  closeAlert(id: string, dismissKey?: string): void;
 
   /**
    * Manually triggers the micro frontend rendering process when using defer-init attribute.
diff --git a/docs/luigi-container-api.md b/docs/luigi-container-api.md
index 71a2dda932..d83c3b4b71 100644
--- a/docs/luigi-container-api.md
+++ b/docs/luigi-container-api.md
@@ -536,7 +536,7 @@ A function that notifies the microfrontend that the opened alert has been closed
 #### Parameters
 
 *   `id` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** the id of the opened alert
-*   `dismissKey` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)** the key specifying which dismiss link was clicked on the alert message
+*   `dismissKey` **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/String)?** the key specifying which dismiss link was clicked on the alert message (optional)
 
 #### Examples
 
diff --git a/docs/luigi-element-api.md b/docs/luigi-element-api.md
index 229d5734a7..57db546396 100644
--- a/docs/luigi-element-api.md
+++ b/docs/luigi-element-api.md
@@ -62,7 +62,7 @@ Base class for Luigi web component micro frontends.
 
 #### afterInit
 
-Override to execute logic after initialization of the web component, i.e.
+Override to execute logic after initialization of the web component, i.e.
 after internal rendering and all context data set.
 
 ##### Parameters
@@ -101,7 +101,7 @@ Query selector operating on shadow root.
 
 ### html
 
-Html string processing according to luigi functionality.
+Html string processing according to luigi functionality.
 Also useful in combination with LitElement VS Code plugins.
 
 #### Parameters