diff --git a/news/714.bugfix b/news/714.bugfix
new file mode 100644
index 000000000..aec0e46e8
--- /dev/null
+++ b/news/714.bugfix
@@ -0,0 +1 @@
+Fix migrate_base_class_to_new_class util to remove Acquisition wrappers. @davisagli
diff --git a/plone/app/contenttypes/utils.py b/plone/app/contenttypes/utils.py
index 1e4ccde0f..7c9aace2e 100644
--- a/plone/app/contenttypes/utils.py
+++ b/plone/app/contenttypes/utils.py
@@ -1,3 +1,4 @@
+from Acquisition import aq_base
 from plone.dexterity.interfaces import IDexterityContent
 from plone.dexterity.interfaces import IDexterityFTI
 from plone.folder.interfaces import IOrdering
@@ -97,7 +98,7 @@ def migrate_base_class_to_new_class(
         parent = obj.__parent__
         parent._delOb(obj_id)
         obj.__class__ = new_class
-        parent._setOb(obj_id, obj)
+        parent._setOb(obj_id, aq_base(obj))
 
     is_container = isinstance(obj, BTreeFolder2Base)