diff --git a/packages/app-shell/src/app-shell.js b/packages/app-shell/src/app-shell.js
index ece65ffe31f1d873d7027ad76d18555769293b64..c0b5e6119830157dddc8d53ebd1d5cedf5ca1b74 100644
--- a/packages/app-shell/src/app-shell.js
+++ b/packages/app-shell/src/app-shell.js
@@ -227,7 +227,8 @@ export class AppShell extends ScopedElementsMixin(AdapterLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String, reflect: true },
             src: { type: String },
             basePath: { type: String, attribute: 'base-path' },
@@ -249,7 +250,7 @@ export class AppShell extends ScopedElementsMixin(AdapterLitElement) {
             buildUrl: { type: String, attribute: "build-url" },
             buildTime: { type: String, attribute: "build-time" },
             env: { type: String },
-        });
+        };
     }
 
     _updateAuth(login) {
diff --git a/packages/app-shell/src/auth-menu-button.js b/packages/app-shell/src/auth-menu-button.js
index c8908443f95a86bd10fb322120590bfab61e638d..8d86bd852c9fae4a78b2c16362254dc9793d66db 100644
--- a/packages/app-shell/src/auth-menu-button.js
+++ b/packages/app-shell/src/auth-menu-button.js
@@ -28,11 +28,12 @@ export class AuthMenuButton extends ScopedElementsMixin(AdapterLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             showImage: { type: Boolean, attribute: 'show-image' },
             _loginData: { type: Object, attribute: false },
-        });
+        };
     }
 
     onWindowResize() {
diff --git a/packages/app-shell/src/build-info.js b/packages/app-shell/src/build-info.js
index f84e436ff3cd3bf1ca56f0574b3f7c832f6d5c07..30bb73d3d10e4e6312afcf1d8f4a9b3fd768840a 100644
--- a/packages/app-shell/src/build-info.js
+++ b/packages/app-shell/src/build-info.js
@@ -13,12 +13,13 @@ export class BuildInfo extends AdapterLitElement {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             env: { type: String },
             buildUrl: { type: String, attribute: "build-url" },
             buildTime: { type: String, attribute: "build-time" },
             gitInfo: { type: String, attribute: "git-info" }
-        });
+        };
     }
 
     static get styles() {
diff --git a/packages/app-shell/src/tugraz-logo.js b/packages/app-shell/src/tugraz-logo.js
index de1d7a128235eebf3f2ea58906adc4375c7fec4d..901b07257a4ee7df4744625ae7112281327ed259 100644
--- a/packages/app-shell/src/tugraz-logo.js
+++ b/packages/app-shell/src/tugraz-logo.js
@@ -14,9 +14,10 @@ export class TUGrazLogo extends AdapterLitElement {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String }
-        });
+        };
     }
 
     update(changedProperties) {
diff --git a/packages/auth/src/auth-keycloak.js b/packages/auth/src/auth-keycloak.js
index 629daae8429169aea3cd31552b2160267d02482f..b59dd2cfc759f4d5abf20ece07779e74739dabaa 100644
--- a/packages/auth/src/auth-keycloak.js
+++ b/packages/auth/src/auth-keycloak.js
@@ -148,7 +148,8 @@ export class AuthKeycloak extends AdapterLitElement {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             forceLogin: { type: Boolean, attribute: 'force-login' },
             tryLogin: { type: Boolean, attribute: 'try-login' },
@@ -166,7 +167,7 @@ export class AuthKeycloak extends AdapterLitElement {
             silentCheckSsoRedirectUri: { type: String, attribute: 'silent-check-sso-redirect-uri' },
             scope: { type: String },
             idpHint: { type: String, attribute: 'idp-hint' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/packages/auth/src/dbp-auth-demo.js b/packages/auth/src/dbp-auth-demo.js
index 621227b564ba7d0df72b5528d06a4fa9c384d721..f31c31b85c45e70f0695787900ba2980d4eca190 100644
--- a/packages/auth/src/dbp-auth-demo.js
+++ b/packages/auth/src/dbp-auth-demo.js
@@ -22,10 +22,11 @@ class AuthDemo extends ScopedElementsMixin(DBPLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     update(changedProperties) {
diff --git a/packages/check-in-place-select/src/check-in-place-select.js b/packages/check-in-place-select/src/check-in-place-select.js
index 888a24829a7ff7e26abb8059ea8bc4856b0082d7..27a84b80a001a0142b1c9196ad1b9aa7fd6ed0f2 100644
--- a/packages/check-in-place-select/src/check-in-place-select.js
+++ b/packages/check-in-place-select/src/check-in-place-select.js
@@ -57,7 +57,8 @@ export class CheckInPlaceSelect extends ScopedElementsMixin(AdapterLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             active: { type: Boolean, attribute: false },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
@@ -66,7 +67,7 @@ export class CheckInPlaceSelect extends ScopedElementsMixin(AdapterLitElement) {
             showReloadButton: { type: Boolean, attribute: 'show-reload-button' },
             reloadButtonTitle: { type: String, attribute: 'reload-button-title' },
             showCapacity: { type: Boolean, attribute: 'show-capacity' },
-        });
+        };
     }
 
     clear() {
diff --git a/packages/check-in-place-select/src/dbp-check-in-place-select-demo.js b/packages/check-in-place-select/src/dbp-check-in-place-select-demo.js
index 98d12c10650fc413ce26aeceedcf8b037cf3ef7e..46002a3f6cd807e1bcb8805baa03465b65dc3df7 100644
--- a/packages/check-in-place-select/src/dbp-check-in-place-select-demo.js
+++ b/packages/check-in-place-select/src/dbp-check-in-place-select-demo.js
@@ -24,11 +24,12 @@ export class CheckInPlaceSelectDemo extends ScopedElementsMixin(DBPLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
             noAuth: { type: Boolean, attribute: 'no-auth' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/packages/data-table-view/src/data-table-view.js b/packages/data-table-view/src/data-table-view.js
index bcff4587c9f7caf012d434b3d66dfc4e3320c77b..fb9690ba6da23b303106e15c712759a56c8e7b6f 100644
--- a/packages/data-table-view/src/data-table-view.js
+++ b/packages/data-table-view/src/data-table-view.js
@@ -49,7 +49,8 @@ export class DataTableView extends AdapterLitElement {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             table: { type: Object, attribute: false },
             paging: { type: Boolean },
@@ -62,7 +63,7 @@ export class DataTableView extends AdapterLitElement {
             exportName: { type: String, attribute: 'export-name' },
             columnSearching: { type: Boolean, attribute: 'column-searching'},
             defaultOrder: { type: Array, attribute: 'default-order'}
-        });
+        };
     }
 
     set_columns(cols) {
diff --git a/packages/data-table-view/src/dbp-data-table-view-demo.js b/packages/data-table-view/src/dbp-data-table-view-demo.js
index 368f03f6ef8b819f9ba0789ba26ee4788c067af7..91508ff76e52073541fa74eae004a7eee8d69e8f 100644
--- a/packages/data-table-view/src/dbp-data-table-view-demo.js
+++ b/packages/data-table-view/src/dbp-data-table-view-demo.js
@@ -24,11 +24,12 @@ export class DataTableViewDemo extends ScopedElementsMixin(DBPLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
             noAuth: { type: Boolean, attribute: 'no-auth' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/packages/file-handling/src/dbp-nextcloud-file-picker.js b/packages/file-handling/src/dbp-nextcloud-file-picker.js
index 158af26220fad48945e6b215fc93e0f57a8561e0..c84aef9e4c0069e640b1a82692cfc42f8d7be7a1 100644
--- a/packages/file-handling/src/dbp-nextcloud-file-picker.js
+++ b/packages/file-handling/src/dbp-nextcloud-file-picker.js
@@ -64,7 +64,8 @@ export class NextcloudFilePicker extends ScopedElementsMixin(DBPLitElement) {
      * See: https://lit-element.polymer-project.org/guide/properties#initialize
      */
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             authUrl: { type: String, attribute: 'auth-url' },
             webDavUrl: { type: String, attribute: 'web-dav-url' },
@@ -85,7 +86,7 @@ export class NextcloudFilePicker extends ScopedElementsMixin(DBPLitElement) {
             activeDirectoryACL: { type: String, attribute: false },
             selectAllButton: { type: Boolean, attribute: false },
             abortUploadButton: { type: Boolean, attribute: false },
-        });
+        };
 
     }
 
diff --git a/packages/file-handling/src/file-sink.js b/packages/file-handling/src/file-sink.js
index fec3f1277e774f3122a121bcdf5f89ee725fa7e5..24e93de34eb19999569d0db64e87a9f1a03a26e9 100644
--- a/packages/file-handling/src/file-sink.js
+++ b/packages/file-handling/src/file-sink.js
@@ -50,7 +50,8 @@ export class FileSink extends ScopedElementsMixin(DBPLitElement) {
      * See: https://lit-element.polymer-project.org/guide/properties#initialize
      */
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             context: {type: String, attribute: 'context'},
             lang: {type: String},
             filename: {type: String},
@@ -69,7 +70,7 @@ export class FileSink extends ScopedElementsMixin(DBPLitElement) {
             firstOpen: {type: Boolean, attribute: false},
             nextcloudDefaultDir: {type: String, attribute: 'nextcloud-default'},
             nextcloudDir: {type: String, attribute: false},
-        });
+        };
     }
 
 
diff --git a/packages/file-handling/src/file-source.js b/packages/file-handling/src/file-source.js
index 1119e56eda8e2874b73b62cb584aaa8398cab588..0d72905612b1ee919e427f18fdba4541ef108374 100644
--- a/packages/file-handling/src/file-source.js
+++ b/packages/file-handling/src/file-source.js
@@ -68,7 +68,8 @@ export class FileSource extends ScopedElementsMixin(DBPLitElement) {
      * See: https://lit-element.polymer-project.org/guide/properties#initialize
      */
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             context: { type: String, attribute: 'context'},
             lang: { type: String },
             allowedMimeTypes: { type: String, attribute: 'allowed-mime-types' },
@@ -88,7 +89,7 @@ export class FileSource extends ScopedElementsMixin(DBPLitElement) {
             firstOpen: { type: Boolean, attribute: false },
             nextcloudDefaultDir: { type: String, attribute: 'nextcloud-default' },
             nextcloudDir: { type: String, attribute: false },
-        });
+        };
     }
 
     update(changedProperties) {
diff --git a/packages/knowledge-base-web-page-element-view/src/dbp-knowledge-base-web-page-element-view-demo.js b/packages/knowledge-base-web-page-element-view/src/dbp-knowledge-base-web-page-element-view-demo.js
index 14639b9be38d6ae0ba5041d82d798392179da0cb..d72d83d88b3e1cc7aafbb2c73386c6c2eddd4571 100644
--- a/packages/knowledge-base-web-page-element-view/src/dbp-knowledge-base-web-page-element-view-demo.js
+++ b/packages/knowledge-base-web-page-element-view/src/dbp-knowledge-base-web-page-element-view-demo.js
@@ -24,11 +24,12 @@ export class KnowledgeBaseWebPageElementViewDemo extends ScopedElementsMixin(DBP
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
             noAuth: { type: Boolean, attribute: 'no-auth' },
-        });
+        };
     }
 
     update(changedProperties) {
diff --git a/packages/matomo/src/dbp-matomo-demo.js b/packages/matomo/src/dbp-matomo-demo.js
index dbe1ed35f073d51eb30e23ca2e24334e1834552e..79e4d6757d80175f8708ae7e393776b575db2635 100644
--- a/packages/matomo/src/dbp-matomo-demo.js
+++ b/packages/matomo/src/dbp-matomo-demo.js
@@ -28,13 +28,14 @@ export class MatomoDemo extends ScopedElementsMixin(DBPLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
             matomoUrl: { type: String, attribute: "matomo-url" },
             matomoSiteId: { type: Number, attribute: "matomo-site-id" },
             noAuth: { type: Boolean, attribute: 'no-auth' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/packages/notification/src/notification.js b/packages/notification/src/notification.js
index 5e68e1d5640fe163a83802a9cb394b00ab19659b..9faf5efda5e758cb2b349717bde53098b99e9f27 100644
--- a/packages/notification/src/notification.js
+++ b/packages/notification/src/notification.js
@@ -17,9 +17,10 @@ export class Notification extends DBPLitElement {
      * See: https://lit-element.polymer-project.org/guide/properties#initialize
      */
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/packages/person-profile/src/dbp-person-profile-demo.js b/packages/person-profile/src/dbp-person-profile-demo.js
index 4328ef6a38601ff52d7cf912bcb4053b20c7a9ad..4893e59de6d1accdd8a506860c07f50447f1078b 100644
--- a/packages/person-profile/src/dbp-person-profile-demo.js
+++ b/packages/person-profile/src/dbp-person-profile-demo.js
@@ -30,13 +30,14 @@ export class PersonProfileDemo extends ScopedElementsMixin(DBPLitElement) {
       }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
             person: { type: String, attribute: false },
             selectedPerson: { type: String, attribute: false },
             noAuth: { type: Boolean, attribute: 'no-auth' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/packages/person-select/src/dbp-person-select-demo.js b/packages/person-select/src/dbp-person-select-demo.js
index 30d366790cbc217f8519f7305d86cb45fb20489e..cdfec18ff15c34a666e9746dc70cf7c4985771c7 100644
--- a/packages/person-select/src/dbp-person-select-demo.js
+++ b/packages/person-select/src/dbp-person-select-demo.js
@@ -24,11 +24,12 @@ export class PersonSelectDemo extends ScopedElementsMixin(DBPLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
             noAuth: { type: Boolean, attribute: 'no-auth' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/packages/person-select/src/person-select.js b/packages/person-select/src/person-select.js
index 540d5c490927c64b2a981f3c24988b033e42a8f1..b662067aeb4d7b41a211017a843f5d0eaa99f43d 100644
--- a/packages/person-select/src/person-select.js
+++ b/packages/person-select/src/person-select.js
@@ -55,7 +55,8 @@ export class PersonSelect extends ScopedElementsMixin(AdapterLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             active: { type: Boolean, attribute: false },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
@@ -64,7 +65,7 @@ export class PersonSelect extends ScopedElementsMixin(AdapterLitElement) {
             showReloadButton: { type: Boolean, attribute: 'show-reload-button' },
             reloadButtonTitle: { type: String, attribute: 'reload-button-title' },
             showBirthDate: { type: Boolean, attribute: 'show-birth-date' },
-        });
+        };
     }
 
     clear() {
diff --git a/packages/provider/src/dbp-provider-demo.js b/packages/provider/src/dbp-provider-demo.js
index d76819444fb6d59adb9170fcaf8dfe8e59530774..60c7f0a7e5ec7bdfad273e1b51e34ab31c6e7626 100644
--- a/packages/provider/src/dbp-provider-demo.js
+++ b/packages/provider/src/dbp-provider-demo.js
@@ -144,7 +144,8 @@ class DemoConsumer extends DBPLitElement {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
             foo: { type: String },
@@ -152,7 +153,7 @@ class DemoConsumer extends DBPLitElement {
             gong: { type: String },
             borderColor: { type: String, attribute: 'border-color' },
             ping: { type: String }
-        });
+        };
     }
 
     attributeChangedCallback(name, oldValue, newValue) {
diff --git a/toolkit-showcase/src/dbp-check-in-place-select-demo-activity.js b/toolkit-showcase/src/dbp-check-in-place-select-demo-activity.js
index 1c4d95195e2bdfe76eb0896b5753d7cc86ebc6a6..d759332b73ff97570895c5a06554f095b4c192f6 100644
--- a/toolkit-showcase/src/dbp-check-in-place-select-demo-activity.js
+++ b/toolkit-showcase/src/dbp-check-in-place-select-demo-activity.js
@@ -23,10 +23,11 @@ class DbpActivityNameDemoActivity extends ScopedElementsMixin(AdapterLitElement)
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-common-demo-activity.js b/toolkit-showcase/src/dbp-common-demo-activity.js
index 91cc10a5ba25ce3911e537bc82aa428c0f534fee..b7f49e7a15f5ffe1f9b438edc6be5473a3978774 100644
--- a/toolkit-showcase/src/dbp-common-demo-activity.js
+++ b/toolkit-showcase/src/dbp-common-demo-activity.js
@@ -23,10 +23,11 @@ class DbpCommonDemoActivity extends ScopedElementsMixin(AdapterLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-data-table-view-demo-activity.js b/toolkit-showcase/src/dbp-data-table-view-demo-activity.js
index dee1780f846a1ba6a34976a94401abe81bc65657..30579ae2015c6495056b53f1be0480ddea2214d0 100644
--- a/toolkit-showcase/src/dbp-data-table-view-demo-activity.js
+++ b/toolkit-showcase/src/dbp-data-table-view-demo-activity.js
@@ -23,10 +23,11 @@ class DbpActivityNameDemoActivity extends ScopedElementsMixin(AdapterLitElement)
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-demo-template.js b/toolkit-showcase/src/dbp-demo-template.js
index f7ae5bd03f5f591bfd824e38af1a68871c61db43..da2a3f3be68166975a8e2671b2350507617ae922 100644
--- a/toolkit-showcase/src/dbp-demo-template.js
+++ b/toolkit-showcase/src/dbp-demo-template.js
@@ -24,10 +24,11 @@ class DbpActivityNameDemoActivity extends ScopedElementsMixin(AdapterLitElement)
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-file-handling-demo-activity.js b/toolkit-showcase/src/dbp-file-handling-demo-activity.js
index fbc6d984fa2206de7c784a95580dbd7cd33169bc..f796324c4a549c762948d1bbd08fdee9ce07159f 100644
--- a/toolkit-showcase/src/dbp-file-handling-demo-activity.js
+++ b/toolkit-showcase/src/dbp-file-handling-demo-activity.js
@@ -23,10 +23,11 @@ class DbpFileHandlingDemoActivity extends ScopedElementsMixin(AdapterLitElement)
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-knowledge-base-web-page-element-view-demo-activity.js b/toolkit-showcase/src/dbp-knowledge-base-web-page-element-view-demo-activity.js
index 548c8ec694b21569b95f291542a1496e081913f4..281a4ce5af43b6f98037c4dc3d092e30d11af146 100644
--- a/toolkit-showcase/src/dbp-knowledge-base-web-page-element-view-demo-activity.js
+++ b/toolkit-showcase/src/dbp-knowledge-base-web-page-element-view-demo-activity.js
@@ -23,10 +23,11 @@ class KnowledgeBaseWebPageElementViewDemoActivity extends ScopedElementsMixin(Ad
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-language-select-demo-activity.js b/toolkit-showcase/src/dbp-language-select-demo-activity.js
index 3d84c6c92b647488e072fe625e8473207ca65d1c..d92c2a1fa2092f6f4e3e7c0e11f69d3df37013e2 100644
--- a/toolkit-showcase/src/dbp-language-select-demo-activity.js
+++ b/toolkit-showcase/src/dbp-language-select-demo-activity.js
@@ -23,10 +23,11 @@ class DbpLanguageSelectDemoActivity extends ScopedElementsMixin(AdapterLitElemen
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-matomo-demo-activity.js b/toolkit-showcase/src/dbp-matomo-demo-activity.js
index e1a49d9895b897b1f97818238da05e65676dc7f2..54d7a4964f229b6f6c9dafd3fa20ea8191f50b0b 100644
--- a/toolkit-showcase/src/dbp-matomo-demo-activity.js
+++ b/toolkit-showcase/src/dbp-matomo-demo-activity.js
@@ -23,10 +23,11 @@ class DbpMatomoDemoActivity extends ScopedElementsMixin(AdapterLitElement) {
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-notification-demo-activity.js b/toolkit-showcase/src/dbp-notification-demo-activity.js
index b919037022c8e427b2a50b8ac5ccea069eaf9b98..841b55ae377c6afe069ba65d7011d9640d62c8b2 100644
--- a/toolkit-showcase/src/dbp-notification-demo-activity.js
+++ b/toolkit-showcase/src/dbp-notification-demo-activity.js
@@ -23,10 +23,11 @@ class DbpNotificationDemoActivity extends ScopedElementsMixin(AdapterLitElement)
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-person-profile-demo-activity.js b/toolkit-showcase/src/dbp-person-profile-demo-activity.js
index 6ee3a02f6ffd651a111f66e6a30f2e4cf7ace92c..db8a69345776db486c6429a64df89eb83d034b7d 100644
--- a/toolkit-showcase/src/dbp-person-profile-demo-activity.js
+++ b/toolkit-showcase/src/dbp-person-profile-demo-activity.js
@@ -23,10 +23,11 @@ class DbpPersonProfileDemoActivity extends ScopedElementsMixin(AdapterLitElement
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-person-select-demo-activity.js b/toolkit-showcase/src/dbp-person-select-demo-activity.js
index f2cdd7dbc06a290076224498aee9b7237426f30d..641c49bd40a56fff6cd845a9cfcdcd23866edb51 100644
--- a/toolkit-showcase/src/dbp-person-select-demo-activity.js
+++ b/toolkit-showcase/src/dbp-person-select-demo-activity.js
@@ -23,10 +23,11 @@ class DbpPersonSelectDemoActivity extends ScopedElementsMixin(AdapterLitElement)
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {
diff --git a/toolkit-showcase/src/dbp-qr-code-scanner-demo-activity.js b/toolkit-showcase/src/dbp-qr-code-scanner-demo-activity.js
index 73d679fab59855e0ad1ca1f0297b30745a9eeabd..edcfb693ce7921163c296b4af3452f347bb772bc 100644
--- a/toolkit-showcase/src/dbp-qr-code-scanner-demo-activity.js
+++ b/toolkit-showcase/src/dbp-qr-code-scanner-demo-activity.js
@@ -23,10 +23,11 @@ class DbpQrCodeScannerDemoActivity extends ScopedElementsMixin(AdapterLitElement
     }
 
     static get properties() {
-        return this.getProperties({
+        return {
+            ...super.properties,
             lang: { type: String },
             entryPointUrl: { type: String, attribute: 'entry-point-url' },
-        });
+        };
     }
 
     connectedCallback() {