diff --git a/src/Extensions/LeftAndMainSubsites.php b/src/Extensions/LeftAndMainSubsites.php
index 760623f5..ccebef68 100644
--- a/src/Extensions/LeftAndMainSubsites.php
+++ b/src/Extensions/LeftAndMainSubsites.php
@@ -215,11 +215,16 @@ public function shouldChangeSubsite($adminClass, $recordSubsiteID, $currentSubsi
 
     /**
      * Check if the current controller is accessible for this user on this subsite.
+     *
+     * @param Member $member
      */
-    public function canAccess()
+    public function canAccess(Member $member = null)
     {
+        if (!$member) {
+            $member = Security::getCurrentUser();
+        }
+
         // Admin can access everything, no point in checking.
-        $member = Security::getCurrentUser();
         if ($member
             && (Permission::checkMember($member, 'ADMIN') // 'Full administrative rights'
                 || Permission::checkMember($member, 'CMS_ACCESS_LeftAndMain') // 'Access to all CMS sections'
@@ -236,10 +241,12 @@ public function canAccess()
     /**
      * Prevent accessing disallowed resources. This happens after onBeforeInit has executed,
      * so all redirections should've already taken place.
+     *
+     * @param Member $member
      */
-    public function alternateAccessCheck()
+    public function alternateAccessCheck(Member $member = null)
     {
-        return $this->owner->canAccess();
+        return $this->owner->canAccess($member);
     }
 
     /**
diff --git a/tests/php/LeftAndMainSubsitesTest.php b/tests/php/LeftAndMainSubsitesTest.php
index 09df18f7..ea60db5a 100644
--- a/tests/php/LeftAndMainSubsitesTest.php
+++ b/tests/php/LeftAndMainSubsitesTest.php
@@ -9,6 +9,7 @@
 use SilverStripe\Core\Config\Config;
 use SilverStripe\Dev\FunctionalTest;
 use SilverStripe\Security\Member;
+use SilverStripe\Subsites\Extensions\LeftAndMainSubsites;
 use SilverStripe\Subsites\Model\Subsite;
 use SilverStripe\Subsites\State\SubsiteState;
 
@@ -100,4 +101,14 @@ public function testShouldChangeSubsite()
         $this->assertTrue($l->shouldChangeSubsite(CMSPageEditController::class, 1, 5));
         $this->assertFalse($l->shouldChangeSubsite(CMSPageEditController::class, 1, 1));
     }
+
+    public function testCanAccessWithPassedMember()
+    {
+        $memberID = $this->logInWithPermission('ADMIN');
+        $member = Member::get()->byID($memberID);
+
+        /** @var LeftAndMain&LeftAndMainSubsites $leftAndMain */
+        $leftAndMain = new LeftAndMain();
+        $this->assertTrue($leftAndMain->canAccess($member));
+    }
 }