diff --git a/src/controllers/DiagnosticsController.php b/src/controllers/DiagnosticsController.php
index b081e132..ab8e0f04 100755
--- a/src/controllers/DiagnosticsController.php
+++ b/src/controllers/DiagnosticsController.php
@@ -28,23 +28,13 @@ public function beforeAction($action): bool
 
     public function actionIndex(string $path): Response
     {
-        Craft::$app->getView()->registerAssetBundle(BlitzAsset::class);
-
         Sprig::bootstrap();
         Sprig::$core->components->setConfig(['requestClass' => 'busy']);
 
-        $siteId = null;
-        $site = Craft::$app->getRequest()->getParam('site');
-        if ($site) {
-            $site = Craft::$app->getSites()->getSiteByHandle($site);
-            $siteId = $site ? $site->id : null;
-        }
-        if (empty($siteId)) {
-            $siteId = Craft::$app->getSites()->getCurrentSite()->id;
-        }
+        Craft::$app->getView()->registerAssetBundle(BlitzAsset::class);
 
         return $this->renderTemplate('blitz/_utilities/diagnostics/' . $path, [
-            'siteId' => $siteId,
+            'siteId' => DiagnosticsHelper::getSiteId(),
         ]);
     }
 
diff --git a/src/helpers/DiagnosticsHelper.php b/src/helpers/DiagnosticsHelper.php
index 30cc12d4..782ec7f0 100644
--- a/src/helpers/DiagnosticsHelper.php
+++ b/src/helpers/DiagnosticsHelper.php
@@ -29,6 +29,21 @@
  */
 class DiagnosticsHelper
 {
+    public static function getSiteId(): ?int
+    {
+        $siteId = null;
+        $site = Craft::$app->getRequest()->getParam('site');
+        if ($site) {
+            $site = Craft::$app->getSites()->getSiteByHandle($site);
+            $siteId = $site ? $site->id : null;
+        }
+        if (empty($siteId)) {
+            $siteId = Craft::$app->getSites()->getCurrentSite()->id;
+        }
+
+        return $siteId;
+    }
+
     public static function getPagesCount(int $siteId): int
     {
         return CacheRecord::find()
diff --git a/src/utilities/DiagnosticsUtility.php b/src/utilities/DiagnosticsUtility.php
index e40af53c..a5195610 100644
--- a/src/utilities/DiagnosticsUtility.php
+++ b/src/utilities/DiagnosticsUtility.php
@@ -8,6 +8,7 @@
 use Craft;
 use craft\base\Utility;
 use putyourlightson\blitz\assets\BlitzAsset;
+use putyourlightson\blitz\helpers\DiagnosticsHelper;
 
 /**
  * @since 4.10.0
@@ -51,18 +52,8 @@ public static function contentHtml(): string
     {
         Craft::$app->getView()->registerAssetBundle(BlitzAsset::class);
 
-        $siteId = null;
-        $site = Craft::$app->getRequest()->getParam('site');
-        if ($site) {
-            $site = Craft::$app->getSites()->getSiteByHandle($site);
-            $siteId = $site ? $site->id : null;
-        }
-        if (empty($siteId)) {
-            $siteId = Craft::$app->getSites()->getCurrentSite()->id;
-        }
-
         return Craft::$app->getView()->renderTemplate('blitz/_utilities/diagnostics/', [
-            'siteId' => $siteId,
+            'siteId' => DiagnosticsHelper::getSiteId(),
         ]);
     }
 }