diff --git a/wagtail/admin/compare.py b/wagtail/admin/compare.py
index dc7a416e62..8f8747eea2 100644
--- a/wagtail/admin/compare.py
+++ b/wagtail/admin/compare.py
@@ -328,7 +328,7 @@ class ForeignObjectComparison(FieldComparison):
             if obj_a:
                 return escape(force_str(obj_a))
             else:
-                return mark_safe(_("None"))
+                return _("None")
 
 
 class ChildRelationComparison: