diff -Naur vendor/ezsystems/ezplatform-connector-dam/src/lib/FieldType/ImageAsset/Value.php vendor/ezsystems/ezplatform-connector-dam/src/lib/FieldType/ImageAsset/Value.php
--- vendor/ezsystems/ezplatform-connector-dam/src/lib/FieldType/ImageAsset/Value.php	2020-11-19 13:53:45.000000000 +0100
+++ vendor/ezsystems/ezplatform-connector-dam/src/lib/FieldType/ImageAsset/Value.php	2020-11-19 13:06:56.000000000 +0100
@@ -16,7 +16,7 @@
     public $source;
 
     public function __construct(
-        $destinationContentId = null,
+        int $destinationContentId = null,
         ?string $alternativeText = null,
         ?string $source = null
     ) {
diff -Naur vendor/ezsystems/ezplatform-connector-dam/src/lib/Form/Transformer/ImageAssetValueTransformer.php vendor/ezsystems/ezplatform-connector-dam/src/lib/Form/Transformer/ImageAssetValueTransformer.php
--- vendor/ezsystems/ezplatform-connector-dam/src/lib/Form/Transformer/ImageAssetValueTransformer.php	2020-11-19 13:53:45.000000000 +0100
+++ vendor/ezsystems/ezplatform-connector-dam/src/lib/Form/Transformer/ImageAssetValueTransformer.php	2020-11-19 13:57:03.000000000 +0100
@@ -56,7 +56,7 @@
         }
 
         return new Value(
-            $value['destinationContentId'],
+            is_numeric($value['destinationContentId']) ? (int)$value['destinationContentId'] : $value['destinationContentId'],
             $value['alternativeText'],
             $value['source'],
         );