diff --git a/app/Controllers/Patient.php b/app/Controllers/Patient.php
index 121110b..ec61b18 100644
--- a/app/Controllers/Patient.php
+++ b/app/Controllers/Patient.php
@@ -394,8 +394,8 @@ class Patient extends Controller {
     }
 
     private function calculateAgeFromBirthdate($birthdate) {
-        $dob = new DateTime($birthdate);
-        $today = new DateTime();
+        $dob = new \DateTime($birthdate);
+        $today = new \DateTime();
         $diff = $today->diff($dob);
 
         $formattedAge = "{$diff->y} years {$diff->m} months {$diff->d} days";