diff --git a/Task/Schedule.php b/Task/Schedule.php
index ec299f7..6263400 100644
--- a/Task/Schedule.php
+++ b/Task/Schedule.php
@@ -161,6 +161,14 @@ public function setPart(int $position, string $value): self
      */
     public function isDue($currentTime = 'now'): bool
     {
+        if (is_string($currentTime)) {
+            trigger_deprecation(
+                'rewieer/taskschedulerbundle',
+                '0.12',
+                'Calling isDue() with a string is deprecated, use a DateTimeInteface instance instead'
+            );
+        }
+
         return $this->cron->isDue($currentTime);
     }
 }
diff --git a/Task/Scheduler.php b/Task/Scheduler.php
index d5968c0..eaebb14 100644
--- a/Task/Scheduler.php
+++ b/Task/Scheduler.php
@@ -10,6 +10,7 @@
 
 namespace Rewieer\TaskSchedulerBundle\Task;
 
+use DateTime;
 use Rewieer\TaskSchedulerBundle\Event\EventDispatcher;
 
 class Scheduler
@@ -39,6 +40,10 @@ public function run($currentTime = 'now'): void
     {
         $this->dispatcher->dispatch(SchedulerEvents::ON_START);
 
+        if (is_string($currentTime)) {
+            $currentTime = new DateTime($currentTime);
+        }
+
         foreach ($this->tasks as $task) {
             if ($task->isDue($currentTime)) {
                 $this->runTask($task);
diff --git a/composer.json b/composer.json
index a76ce53..3063eb9 100644
--- a/composer.json
+++ b/composer.json
@@ -10,6 +10,7 @@
   "keywords": ["cron", "task", "scheduler", "symfony", "bundle"],
   "require": {
     "php": "^7.4|^8.1",
+    "symfony/deprecation-contracts": "^2.5|^3.4",
     "symfony/framework-bundle": "^5.4|^6.4|^7.0",
     "symfony/console": "^5.3|^6.4|^7.0",
     "dragonmantank/cron-expression": "^3.3"