--- a/src/iconolab/management/commands/importimages.py	Wed Aug 01 18:36:38 2018 +0200
+++ b/src/iconolab/management/commands/importimages.py	Wed Aug 01 19:05:27 2018 +0200
@@ -6,6 +6,7 @@
 from django.conf import settings
 from django.core.management.base import BaseCommand, CommandError
 from django.db import transaction
+from django.utils import text
 from PIL import Image as ImagePIL
 from sorl.thumbnail import get_thumbnail
 
@@ -18,7 +19,10 @@
         raise NotImplementedError
 
     def get_image_dir(self, natural_key, collection):
-        return os.path.join(collection.name, natural_key)
+        return os.path.join(
+            collection.name,
+            text.get_valid_filename(natural_key.replace('|', '__'))
+        )
 
     ##
     def create_item_and_metadata(