diff --git a/apps/theming/lib/Settings/Admin.php b/apps/theming/lib/Settings/Admin.php
index afd74ced21..22ab5650e5 100644
--- a/apps/theming/lib/Settings/Admin.php
+++ b/apps/theming/lib/Settings/Admin.php
@@ -61,7 +61,7 @@ class Admin implements ISettings {
 		$theme = $this->config->getSystemValue('theme', '');
 		if ($theme !== '') {
 			$themable = false;
-			$errorMessage = $this->l->t('You already use a custom theme');
+			$errorMessage = $this->l->t('You are already using a custom theme');
 		}
 
 		$parameters = [
diff --git a/apps/theming/tests/Settings/AdminTest.php b/apps/theming/tests/Settings/AdminTest.php
index 73339cf86b..d4f5490d35 100644
--- a/apps/theming/tests/Settings/AdminTest.php
+++ b/apps/theming/tests/Settings/AdminTest.php
@@ -112,8 +112,8 @@ class AdminTest extends TestCase {
 		$this->l10n
 			->expects($this->once())
 			->method('t')
-			->with('You already use a custom theme')
-			->willReturn('You already use a custom theme');
+			->with('You are already using a custom theme')
+			->willReturn('You are already using a custom theme');
 		$this->themingDefaults
 			->expects($this->once())
 			->method('getEntity')
@@ -137,7 +137,7 @@ class AdminTest extends TestCase {
 			->willReturn('/my/route');
 		$params = [
 			'themable' => false,
-			'errorMessage' => 'You already use a custom theme',
+			'errorMessage' => 'You are already using a custom theme',
 			'name' => 'MyEntity',
 			'url' => 'https://example.com',
 			'slogan' => 'MySlogan',