diff --git a/longs/tables.py b/longs/tables.py
index cb191f15..a256bdb3 100755
--- a/longs/tables.py
+++ b/longs/tables.py
@@ -42,9 +42,9 @@ class LongSeriesImageColumn(tables.Column):
         image_object = obj.image
         try:
             thumbnailer = get_thumbnailer(image_object)
-            return format_html('<img src="/media/{}" /><br/>[{}]', thumbnailer["exam-list"], len(value))
+            return format_html('<img src="/media/{}" /><br/>[{}]', thumbnailer["exam-list"], value.count())
         except InvalidImageFormatError:
-            return format_html('<span title="{}">Invalid image url<span><br/>[{}]', image_object, len(value))
+            return format_html('<span title="{}">Invalid image url<span><br/>[{}]', image_object, value.count())
 
 
 class LongTable(tables.Table):