diff --git a/system/Session/Session.php b/system/Session/Session.php
index 1c3824928775..f1901377d0d5 100644
--- a/system/Session/Session.php
+++ b/system/Session/Session.php
@@ -274,6 +274,8 @@ private function removeOldSessionCookie(): void
     public function destroy()
     {
         if (ENVIRONMENT === 'testing') {
+            $_SESSION = [];
+
             return;
         }
 
diff --git a/tests/system/Session/SessionTest.php b/tests/system/Session/SessionTest.php
index 3b7cd3860ccd..e66b3f868f97 100644
--- a/tests/system/Session/SessionTest.php
+++ b/tests/system/Session/SessionTest.php
@@ -328,6 +328,19 @@ public function testSetMagicMethod(): void
         $this->assertSame('bar', $_SESSION['foo']);
     }
 
+    public function testDestroyClearsSessionInTesting(): void
+    {
+        $session = $this->getInstance();
+        $session->start();
+
+        $session->set('foo', 'bar');
+        $this->assertSame('bar', $_SESSION['foo']);
+
+        $session->destroy();
+
+        $this->assertSame([], $_SESSION);
+    }
+
     public function testCanFlashData(): void
     {
         $session = $this->getInstance();