diff --git a/runtime/lib/collection/PropelCollection.php b/runtime/lib/collection/PropelCollection.php
index 26637b5f0..8a6562d56 100644
--- a/runtime/lib/collection/PropelCollection.php
+++ b/runtime/lib/collection/PropelCollection.php
@@ -25,7 +25,7 @@
  * @author     Francois Zaninotto
  * @package    propel.runtime.collection
  */
-class PropelCollection extends ArrayObject implements Serializable
+class PropelCollection extends ArrayObject
 {
     /**
      * @var       string
@@ -354,29 +354,18 @@ public function diff(PropelCollection $collection)
         return $diff;
     }
 
-    // Serializable interface
-
-    /**
-     * @return string
-     */
-    public function serialize(): string
+    public function __serialize(): array
     {
-        $repr = array(
+        return [
             'data'   => $this->getArrayCopy(),
             'model'  => $this->model,
-        );
-
-        return serialize($repr);
+        ];
     }
 
-    /**
-     * @param string $data
-     */
-    public function unserialize($data): void
+    public function __unserialize(array $data): void
     {
-        $repr = unserialize($data);
-        $this->exchangeArray($repr['data']);
-        $this->model = $repr['model'];
+        $this->exchangeArray($data['data']);
+        $this->model = $data['model'];
     }
 
     // IteratorAggregate method
diff --git a/runtime/lib/collection/PropelOnDemandCollection.php b/runtime/lib/collection/PropelOnDemandCollection.php
index 6ed0063e6..e2d4eb20a 100644
--- a/runtime/lib/collection/PropelOnDemandCollection.php
+++ b/runtime/lib/collection/PropelOnDemandCollection.php
@@ -114,18 +114,15 @@ public function offsetUnset($offset)
     /**
      * @throws PropelException
      */
-    public function serialize()
+    public function __serialize(): array
     {
         throw new PropelException('The On Demand Collection cannot be serialized');
     }
 
     /**
      * @throws PropelException
-     * @param  string          $data
-     *
-     * @return void
      */
-    public function unserialize($data)
+    public function __unserialize(array $data): void
     {
         throw new PropelException('The On Demand Collection cannot be serialized');
     }