diff --git a/Block/Zone/Response.php b/Block/Zone/Response.php
index 3885a6d..f2cc405 100644
--- a/Block/Zone/Response.php
+++ b/Block/Zone/Response.php
@@ -75,7 +75,7 @@ public function getEsiUrlList(): array
         $list = [];
 
         $pattern = '/]*src=[\'"]([^\'"]+)[\'"][^>]*>/';
-        if (preg_match_all($pattern, $this->response->getContent(), $matches)) {
+        if (preg_match_all($pattern, (string) $this->response->getContent(), $matches)) {
             $list = $matches[1];
         }
 
diff --git a/Observer/AddToolbar.php b/Observer/AddToolbar.php
index 7e04341..211b7cb 100644
--- a/Observer/AddToolbar.php
+++ b/Observer/AddToolbar.php
@@ -145,9 +145,9 @@ private function buildToolbar(
 
         // Add the last toolbars to the content
         if ($area === Area::AREA_FRONTEND || $area === Area::AREA_ADMINHTML && $this->configHelper->isEnabledAdmin()) {
-            $content = $response->getContent();
+            $content = (string) $response->getContent();
             $endTag = '</body';
-            if (strpos($content, $endTag) !== false) {
+            if (str_contains($content, $endTag)) {
                 $toolbarsContent = $this->getToolbarsBlock()->toHtml();
                 $content = str_replace($endTag, $toolbarsContent . $endTag, $content);
                 $response->setContent($content);
diff --git a/view/base/templates/zone/response.phtml b/view/base/templates/zone/response.phtml
index 8a78e15..65243fc 100644
--- a/view/base/templates/zone/response.phtml
+++ b/view/base/templates/zone/response.phtml
@@ -5,7 +5,7 @@ use Smile\DebugToolbar\Block\Zone\Response;
 /** @var Response $block */
 $response = $block->getResponse();
 
-$length = mb_strlen($response->getContent());
+$length = mb_strlen((string) $response->getContent());
 
 $headers = [];
 foreach ($response->getHeaders() as $header) {