diff --git a/app/assets/javascripts/admin/addon/adapters/api-key.js b/app/assets/javascripts/admin/addon/adapters/api-key.js
index 860e4c50692..6e1ad0eb327 100644
--- a/app/assets/javascripts/admin/addon/adapters/api-key.js
+++ b/app/assets/javascripts/admin/addon/adapters/api-key.js
@@ -1,13 +1,13 @@
-import RESTAdapter from "discourse/adapters/rest";
+import RestAdapter from "discourse/adapters/rest";
 
-export default RESTAdapter.extend({
-  jsonMode: true,
+export default class ApiKey extends RestAdapter {
+  jsonMode = true;
 
   basePath() {
     return "/admin/api/";
-  },
+  }
 
   apiNameFor() {
     return "key";
-  },
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/adapters/build-plugin.js b/app/assets/javascripts/admin/addon/adapters/build-plugin.js
index 3a81ab4e573..98b875ba94b 100644
--- a/app/assets/javascripts/admin/addon/adapters/build-plugin.js
+++ b/app/assets/javascripts/admin/addon/adapters/build-plugin.js
@@ -1,11 +1,11 @@
 import RestAdapter from "discourse/adapters/rest";
 
 export default function buildPluginAdapter(pluginName) {
-  return RestAdapter.extend({
+  return class extends RestAdapter {
     pathFor(store, type, findArgs) {
       return (
-        "/admin/plugins/" + pluginName + this._super(store, type, findArgs)
+        "/admin/plugins/" + pluginName + super.pathFor(store, type, findArgs)
       );
-    },
-  });
+    }
+  };
 }
diff --git a/app/assets/javascripts/admin/addon/adapters/customization-base.js b/app/assets/javascripts/admin/addon/adapters/customization-base.js
index 272103ee8a8..d20f15d1dca 100644
--- a/app/assets/javascripts/admin/addon/adapters/customization-base.js
+++ b/app/assets/javascripts/admin/addon/adapters/customization-base.js
@@ -1,7 +1,7 @@
 import RestAdapter from "discourse/adapters/rest";
 
-export default RestAdapter.extend({
+export default class CustomizationBase extends RestAdapter {
   basePath() {
     return "/admin/customize/";
-  },
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/adapters/email-style.js b/app/assets/javascripts/admin/addon/adapters/email-style.js
index 12919f04b0d..e4465ef56eb 100644
--- a/app/assets/javascripts/admin/addon/adapters/email-style.js
+++ b/app/assets/javascripts/admin/addon/adapters/email-style.js
@@ -1,7 +1,7 @@
 import RestAdapter from "discourse/adapters/rest";
 
-export default RestAdapter.extend({
+export default class EmailStyle extends RestAdapter {
   pathFor() {
     return "/admin/customize/email_style";
-  },
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/adapters/embedding.js b/app/assets/javascripts/admin/addon/adapters/embedding.js
index ba3fb816b80..966098fd4d1 100644
--- a/app/assets/javascripts/admin/addon/adapters/embedding.js
+++ b/app/assets/javascripts/admin/addon/adapters/embedding.js
@@ -1,7 +1,7 @@
 import RestAdapter from "discourse/adapters/rest";
 
-export default RestAdapter.extend({
+export default class Embedding extends RestAdapter {
   pathFor() {
     return "/admin/customize/embedding";
-  },
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/adapters/staff-action-log.js b/app/assets/javascripts/admin/addon/adapters/staff-action-log.js
index d281f9746be..9a9d1d6c0b4 100644
--- a/app/assets/javascripts/admin/addon/adapters/staff-action-log.js
+++ b/app/assets/javascripts/admin/addon/adapters/staff-action-log.js
@@ -1,7 +1,7 @@
 import RestAdapter from "discourse/adapters/rest";
 
-export default RestAdapter.extend({
+export default class StaffActionLog extends RestAdapter {
   basePath() {
     return "/admin/logs/";
-  },
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/adapters/tag-group.js b/app/assets/javascripts/admin/addon/adapters/tag-group.js
index 4c12654d967..4caa9172b92 100644
--- a/app/assets/javascripts/admin/addon/adapters/tag-group.js
+++ b/app/assets/javascripts/admin/addon/adapters/tag-group.js
@@ -1,5 +1,5 @@
 import RestAdapter from "discourse/adapters/rest";
 
-export default RestAdapter.extend({
-  jsonMode: true,
-});
+export default class TagGroup extends RestAdapter {
+  jsonMode = true;
+}
diff --git a/app/assets/javascripts/admin/addon/adapters/theme.js b/app/assets/javascripts/admin/addon/adapters/theme.js
index cf34ab42f5f..66f901b2cdb 100644
--- a/app/assets/javascripts/admin/addon/adapters/theme.js
+++ b/app/assets/javascripts/admin/addon/adapters/theme.js
@@ -1,9 +1,10 @@
 import RestAdapter from "discourse/adapters/rest";
 
-export default RestAdapter.extend({
+export default class Theme extends RestAdapter {
+  jsonMode = true;
   basePath() {
     return "/admin/";
-  },
+  }
 
   afterFindAll(results) {
     let map = {};
@@ -20,7 +21,5 @@ export default RestAdapter.extend({
       theme.set("parentThemes", mappedParents);
     });
     return results;
-  },
-
-  jsonMode: true,
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/adapters/web-hook-event.js b/app/assets/javascripts/admin/addon/adapters/web-hook-event.js
index 1acd38386ba..8a6fa2b082d 100644
--- a/app/assets/javascripts/admin/addon/adapters/web-hook-event.js
+++ b/app/assets/javascripts/admin/addon/adapters/web-hook-event.js
@@ -1,7 +1,7 @@
-import RESTAdapter from "discourse/adapters/rest";
+import RestAdapter from "discourse/adapters/rest";
 
-export default RESTAdapter.extend({
+export default class WebHookEvent extends RestAdapter {
   basePath() {
     return "/admin/api/";
-  },
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/adapters/web-hook.js b/app/assets/javascripts/admin/addon/adapters/web-hook.js
index 1acd38386ba..813f7dbf03b 100644
--- a/app/assets/javascripts/admin/addon/adapters/web-hook.js
+++ b/app/assets/javascripts/admin/addon/adapters/web-hook.js
@@ -1,7 +1,7 @@
-import RESTAdapter from "discourse/adapters/rest";
+import RestAdapter from "discourse/adapters/rest";
 
-export default RESTAdapter.extend({
+export default class WebHook extends RestAdapter {
   basePath() {
     return "/admin/api/";
-  },
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/helpers/disposition-icon.js b/app/assets/javascripts/admin/addon/helpers/disposition-icon.js
index f49d22e2726..80820b0bc63 100644
--- a/app/assets/javascripts/admin/addon/helpers/disposition-icon.js
+++ b/app/assets/javascripts/admin/addon/helpers/disposition-icon.js
@@ -2,7 +2,7 @@ import Helper from "@ember/component/helper";
 import { iconHTML } from "discourse-common/lib/icon-library";
 import { htmlSafe } from "@ember/template";
 
-export default Helper.extend({
+export default class DispositionIcon extends Helper {
   compute([disposition]) {
     if (!disposition) {
       return null;
@@ -24,5 +24,5 @@ export default Helper.extend({
       }
     }
     return htmlSafe(iconHTML(icon, { title }));
-  },
-});
+  }
+}
diff --git a/app/assets/javascripts/admin/addon/services/admin-tools.js b/app/assets/javascripts/admin/addon/services/admin-tools.js
index 59d3a432d14..79944fc1475 100644
--- a/app/assets/javascripts/admin/addon/services/admin-tools.js
+++ b/app/assets/javascripts/admin/addon/services/admin-tools.js
@@ -10,8 +10,8 @@ import { htmlSafe } from "@ember/template";
 // A service that can act as a bridge between the front end Discourse application
 // and the admin application. Use this if you need front end code to access admin
 // modules. Inject it optionally, and if it exists go to town!
-export default Service.extend({
-  dialog: service(),
+export default class AdminToolsService extends Service {
+  @service dialog;
 
   showActionLogs(target, filters) {
     const controller = getOwner(target).lookup(
@@ -20,15 +20,15 @@ export default Service.extend({
     target.transitionToRoute("adminLogs.staffActionLogs").then(() => {
       controller.changeFilters(filters);
     });
-  },
+  }
 
   checkSpammer(userId) {
     return AdminUser.find(userId).then((au) => this.spammerDetails(au));
-  },
+  }
 
   deleteUser(id, formData) {
     return AdminUser.find(id).then((user) => user.destroy(formData));
-  },
+  }
 
   spammerDetails(adminUser) {
     return {
@@ -37,7 +37,7 @@ export default Service.extend({
         adminUser.get("can_be_deleted") &&
         adminUser.get("can_delete_all_posts"),
     };
-  },
+  }
 
   _showControlModal(type, user, opts) {
     opts = opts || {};
@@ -67,15 +67,15 @@ export default Service.extend({
 
       controller.finishedSetup();
     });
-  },
+  }
 
   showSilenceModal(user, opts) {
     this._showControlModal("silence", user, opts);
-  },
+  }
 
   showSuspendModal(user, opts) {
     this._showControlModal("suspend", user, opts);
-  },
+  }
 
   _deleteSpammer(adminUser) {
     // Try loading the email if the site supports it
@@ -131,5 +131,5 @@ export default Service.extend({
         });
       });
     });
-  },
-});
+  }
+}