diff --git a/classes/ComicPressComicPost.inc b/classes/ComicPressComicPost.inc
index efac07e..1daafd9 100644
--- a/classes/ComicPressComicPost.inc
+++ b/classes/ComicPressComicPost.inc
@@ -15,7 +15,13 @@ class ComicPressComicPost {
   	$comicpress = ComicPress::get_instance();
   	$attachments = array();
 		foreach ($comicpress->backends as $backend) {
-			$attachments = array_merge($attachments, call_user_func(array($backend, 'generate_from_post'), $this->post));
+			if (is_string($backend)) {
+				$a = new $backend();
+			}
+			if (is_object($backend)) {
+				$a = $backend;
+			}
+			$attachments = array_merge($attachments, $a->generate_from_post($this->post));
 		}
 		return $attachments;
   }
diff --git a/classes/backends/ComicPressBackendAttachment.inc b/classes/backends/ComicPressBackendAttachment.inc
index ddaca16..cd7a553 100644
--- a/classes/backends/ComicPressBackendAttachment.inc
+++ b/classes/backends/ComicPressBackendAttachment.inc
@@ -31,10 +31,12 @@ class ComicPressBackendAttachment extends ComicPressBackend {
 		return $result;
 	}
 
-	function ComicPressBackendAttachment($attachment) {
-		$this->attachment = $attachment;
-		$this->id = sprintf('%s-%d', $this->root_id, $this->attachment->ID);
-		$this->type = get_post_meta($this->attachment->ID, 'comic_image_type', true);
+	function ComicPressBackendAttachment($attachment = null) {
+		if (!is_null($attachment)) {
+			$this->attachment = $attachment;
+			$this->id = sprintf('%s-%d', $this->root_id, $this->attachment->ID);
+			$this->type = get_post_meta($this->attachment->ID, 'comic_image_type', true);
+		}
 	}
 
 	function dims($size = 'comic') {