diff --git a/src/ldaptools/synchronize.py b/src/ldaptools/synchronize.py
index 492a836..84f84aa 100644
--- a/src/ldaptools/synchronize.py
+++ b/src/ldaptools/synchronize.py
@@ -138,7 +138,7 @@ class Synchronize(object):
     def massage_dn(self, old_dn):
         return old_dn[:-len(self.source_dn)] + self.target_dn
 
-    def get_pivot_attribute(self, entry):
+    def get_pivot_attribute(self, dn, entry):
         '''Find a pivot attribute value for an LDAP entry'''
         for objc, attr in self.pivot_attributes:
             entry['objectclass'] = map(istr, entry['objectclass'])
@@ -146,12 +146,12 @@ class Synchronize(object):
                 try:
                     value = entry[attr]
                 except KeyError:
-                    raise Exception('entry missing pivot attribute %s: %s' % (attr, entry))
+                    raise Exception('entry %s missing pivot attribute %s: %s' % (dn, attr, entry))
                 break
         else:
-            raise Exception('entry has unknown objectclasses %s' % entry['objectclass'])
+            raise Exception('entry %s has unknown objectclasses %s' % (dn, entry['objectclass']))
         if len(value) != 1:
-            raise Exception('entry pivot attribute %s must have only one value' % attr)
+            raise Exception('entry %s pivot attribute %s must have only one value' % (dn, attr))
         if attr in self.case_insensitive_attribute:
             value = map(istr, value)
         return objc, attr, value[0]
@@ -175,7 +175,7 @@ class Synchronize(object):
         out_filters = []
         # Transform input entries into filters
         for dn, entry in entries:
-            objectclass, attr, value = self.get_pivot_attribute(entry)
+            objectclass, attr, value = self.get_pivot_attribute(dn, entry)
             in_dns.append(((attr, value), (dn, entry)))
             filter_tpl = '(&(objectclass=%%s)(%s=%%s))' % attr
             out_filters.append(
@@ -184,7 +184,7 @@ class Synchronize(object):
         # Get existing output entries
         out_dns = {}
         for dn, entry in self.get_target_entries(filterstr=out_filter, attributes=self.attributes):
-            objectclass, attr, value = self.get_pivot_attribute(entry)
+            objectclass, attr, value = self.get_pivot_attribute(dn, entry)
             out_dns[(attr, value)] = dn, entry
         for pivot, (source_dn, entry) in in_dns:
             target_dn = self.massage_dn(source_dn)