diff --git a/src/Control/Director.php b/src/Control/Director.php
index 8c749d1f1..32e6fdf4e 100644
--- a/src/Control/Director.php
+++ b/src/Control/Director.php
@@ -345,7 +345,7 @@ class Director implements TemplateGlobalProvider
                 $handler = function () use ($arguments) {
                     // Redirection
                     $response = new HTTPResponse();
-                    $response->redirect(static::absoluteURL($arguments['Redirect']));
+                    $response->redirect(static::absoluteUrl((string) $arguments['Redirect']));
                     return $response;
                 };
                 break;
diff --git a/src/Control/HTTP.php b/src/Control/HTTP.php
index 1d3f25daa..4ccf5d7b7 100644
--- a/src/Control/HTTP.php
+++ b/src/Control/HTTP.php
@@ -70,7 +70,7 @@ class HTTP
             if (preg_match('/^\w+:/', $url ?? '')) {
                 return $url;
             }
-            return Director::absoluteURL($url);
+            return Director::absoluteURL((string) $url);
         });
     }
 
@@ -87,8 +87,8 @@ class HTTP
      * As of 3.2 $code should be a callable which takes a single parameter and returns the rewritten,
      * for example:
      * <code>
-     * function($url) {
-     *      return Director::absoluteURL($url, true);
+     * function(string $url) {
+     *      return Director::absoluteURL((string) $url, true);
      * }
      * </code>
      *
diff --git a/src/Control/HTTPResponse.php b/src/Control/HTTPResponse.php
index 502d5fbaf..b4fd1e638 100644
--- a/src/Control/HTTPResponse.php
+++ b/src/Control/HTTPResponse.php
@@ -346,7 +346,7 @@ class HTTPResponse
     {
         $headersSent = headers_sent($file, $line);
         $location = $this->getHeader('location');
-        $url = Director::absoluteURL($location);
+        $url = Director::absoluteURL((string) $location);
         $urlATT = Convert::raw2htmlatt($url);
         $urlJS = Convert::raw2js($url);
         $title = (Director::isDev() && $headersSent)
diff --git a/src/Control/RSS/RSSFeed.php b/src/Control/RSS/RSSFeed.php
index 5ab5eae9b..597a1f09a 100644
--- a/src/Control/RSS/RSSFeed.php
+++ b/src/Control/RSS/RSSFeed.php
@@ -199,7 +199,7 @@ class RSSFeed extends ViewableData
      */
     public function Link($action = null)
     {
-        return Controller::join_links(Director::absoluteURL($this->link), $action);
+        return Controller::join_links(Director::absoluteURL((string) $this->link), $action);
     }
 
     /**
diff --git a/src/Control/RSS/RSSFeed_Entry.php b/src/Control/RSS/RSSFeed_Entry.php
index 2ae7099c2..5713b8402 100644
--- a/src/Control/RSS/RSSFeed_Entry.php
+++ b/src/Control/RSS/RSSFeed_Entry.php
@@ -125,7 +125,7 @@ class RSSFeed_Entry extends ViewableData
             return $this->failover->AbsoluteLink();
         } else {
             if ($this->failover->hasMethod('Link')) {
-                return Director::absoluteURL($this->failover->Link());
+                return Director::absoluteURL((string) $this->failover->Link());
             }
         }
 
diff --git a/src/Control/RequestHandler.php b/src/Control/RequestHandler.php
index 76e3580ae..2052b01ba 100644
--- a/src/Control/RequestHandler.php
+++ b/src/Control/RequestHandler.php
@@ -658,7 +658,7 @@ class RequestHandler extends ViewableData
             ?: Director::baseURL();
 
         // Only direct to absolute urls
-        $url = Director::absoluteURL($url);
+        $url = Director::absoluteURL((string) $url);
         return $this->redirect($url);
     }
 }
diff --git a/src/Forms/HTMLEditor/TinyMCEConfig.php b/src/Forms/HTMLEditor/TinyMCEConfig.php
index 2b893d367..80379fc50 100644
--- a/src/Forms/HTMLEditor/TinyMCEConfig.php
+++ b/src/Forms/HTMLEditor/TinyMCEConfig.php
@@ -675,7 +675,7 @@ class TinyMCEConfig extends HTMLEditorConfig implements i18nEntityProvider
                 );
             } elseif (!Director::is_absolute_url($path)) {
                 // Non-absolute urls are made absolute
-                $path = Director::absoluteURL($path);
+                $path = Director::absoluteURL((string) $path);
             }
             $plugins[$plugin] = $path;
         }
diff --git a/src/ORM/DatabaseAdmin.php b/src/ORM/DatabaseAdmin.php
index 07bbce20c..698fe6d3f 100644
--- a/src/ORM/DatabaseAdmin.php
+++ b/src/ORM/DatabaseAdmin.php
@@ -167,7 +167,7 @@ class DatabaseAdmin extends Controller
         }
 
         // Convert to absolute URL
-        return Director::absoluteURL($url, true);
+        return Director::absoluteURL((string) $url, true);
     }
 
     /**
diff --git a/src/Security/PasswordExpirationMiddleware.php b/src/Security/PasswordExpirationMiddleware.php
index 6211c5706..3c6aad33d 100644
--- a/src/Security/PasswordExpirationMiddleware.php
+++ b/src/Security/PasswordExpirationMiddleware.php
@@ -135,7 +135,7 @@ class PasswordExpirationMiddleware implements HTTPMiddleware
         $defaultRedirectUrl = static::config()->get('default_redirect');
 
         if ($sessionRedirectUrl || $defaultRedirectUrl) {
-            $redirectUrl = $this->absoluteUrl($sessionRedirectUrl ?? $defaultRedirectUrl);
+            $redirectUrl = $this->absoluteUrl((string) ($sessionRedirectUrl ?? $defaultRedirectUrl));
         } else {
             $redirectUrl = null;
         }
@@ -153,7 +153,7 @@ class PasswordExpirationMiddleware implements HTTPMiddleware
         $allowedStartswith = static::config()->get('whitelisted_url_startswith');
         if (is_array($allowedStartswith)) {
             foreach ($allowedStartswith as $pattern) {
-                $startswith = $this->absoluteUrl($pattern);
+                $startswith = $this->absoluteUrl((string) $pattern);
 
                 if (strncmp($currentUrl ?? '', $startswith ?? '', strlen($startswith ?? '')) === 0) {
                     return null;
@@ -178,7 +178,7 @@ class PasswordExpirationMiddleware implements HTTPMiddleware
             // add BASE_URL explicitly if not absolute
             $url = Controller::join_links(Director::absoluteBaseURL(), $url);
         } else {
-            $url = Director::absoluteURL($url) ?: Controller::join_links(Director::absoluteBaseURL(), $url);
+            $url = Director::absoluteURL((string) $url) ?: Controller::join_links(Director::absoluteBaseURL(), $url);
         }
 
         if (substr($url ?? '', -1) === '/') {
diff --git a/tests/php/Security/SecurityTest.php b/tests/php/Security/SecurityTest.php
index e094f5747..8ab99e0cc 100644
--- a/tests/php/Security/SecurityTest.php
+++ b/tests/php/Security/SecurityTest.php
@@ -447,7 +447,7 @@ class SecurityTest extends FunctionalTest
         $this->assertEquals(302, $expiredResponse->getStatusCode());
         $this->assertEquals(
             Director::absoluteURL('Security/changepassword') . '?BackURL=test%2Flink',
-            Director::absoluteURL($expiredResponse->getHeader('Location'))
+            Director::absoluteURL((string) $expiredResponse->getHeader('Location'))
         );
         $this->assertEquals(
             $this->idFromFixture(Member::class, 'expiredpassword'),
@@ -517,9 +517,8 @@ class SecurityTest extends FunctionalTest
         $this->assertEquals(302, $response->getStatusCode());
         $this->assertEquals(
             Director::absoluteURL('Security/changepassword'),
-            Director::absoluteURL($response->getHeader('Location'))
+            Director::absoluteURL((string) $response->getHeader('Location'))
         );
-
         // Follow redirection to form without hash in GET parameter
         $this->get('Security/changepassword');
         $this->doTestChangepasswordForm('1nitialPassword', 'changedPassword#123');