diff --git a/bookwyrm/views/books.py b/bookwyrm/views/books.py
index 02cbd1e2..895c7ec9 100644
--- a/bookwyrm/views/books.py
+++ b/bookwyrm/views/books.py
@@ -266,7 +266,9 @@ class Editions(View):
             "editions": editions.filter(**filters).all(),
             "work": work,
             "languages": languages,
-            "formats": set(e.physical_format.lower() for e in editions if e),
+            "formats": set(
+                e.physical_format.lower() for e in editions if e.physical_format
+            ),
         }
         return TemplateResponse(request, "book/editions.html", data)