diff --git a/data/resources/style.css b/data/resources/style.css
index 5d9bcdebbbee3f842bf0bc41af021f6fb5a4b64a..5c789ea44afac9a4ce72da1217971e8d20a92b43 100644
--- a/data/resources/style.css
+++ b/data/resources/style.css
@@ -170,14 +170,6 @@ treeview.polari-server-room-list {
     opacity: 0.3;
 }
 
-/* Differentiate test instance from "normal" ones */
-window.test-instance .content-pane headerbar {
-    background-image: cross-fade(25% -gtk-icontheme('system-run-symbolic'));
-    background-repeat: no-repeat;
-    background-position: 1em center;
-    background-size: 4em;
-}
-
 /* Differentiate snapshot builds from regular ones */
 window.snapshot headerbar { background: none; }
 window.snapshot .titlebar {
diff --git a/src/mainWindow.js b/src/mainWindow.js
index 1aebf5693609d883b5bad67d987232af4b1e0f07..a9fc1e49564a883b6cddbb7098e91b66451967af 100644
--- a/src/mainWindow.js
+++ b/src/mainWindow.js
@@ -76,7 +76,7 @@ class MainWindow extends Adw.ApplicationWindow {
 
         const app = this.application;
         if (app.isTestInstance)
-            this.add_css_class('test-instance');
+            this.add_css_class('devel');
         if (GLib.get_application_name().toLowerCase().includes('snapshot'))
             this.add_css_class('snapshot');