diff --git a/django/core/serializers/python.py b/django/core/serializers/python.py
index 66dbbff3350..5fbb3163f78 100644
--- a/django/core/serializers/python.py
+++ b/django/core/serializers/python.py
@@ -37,7 +37,12 @@ class Serializer(base.Serializer):
     def handle_fk_field(self, obj, field):
         related = getattr(obj, field.name)
         if related is not None:
-            related = getattr(related, field.rel.field_name)
+            if field.rel.field_name == related._meta.pk.name:
+                # Related to remote object via primary key
+                related = related._get_pk_val()
+            else:
+                # Related to remote object via other field
+                related = getattr(related, field.rel.field_name)
         self._current[field.name] = related
     
     def handle_m2m_field(self, obj, field):
diff --git a/django/core/serializers/xml_serializer.py b/django/core/serializers/xml_serializer.py
index 633001f5f06..3e4a6f3e795 100644
--- a/django/core/serializers/xml_serializer.py
+++ b/django/core/serializers/xml_serializer.py
@@ -82,7 +82,13 @@ class Serializer(base.Serializer):
         self._start_relational_field(field)
         related = getattr(obj, field.name)
         if related is not None:
-            self.xml.characters(str(getattr(related, field.rel.field_name)))
+            if field.rel.field_name == related._meta.pk.name:
+                # Related to remote object via primary key
+                related = related._get_pk_val()
+            else:
+                # Related to remote object via other field
+                related = getattr(related, field.rel.field_name)
+            self.xml.characters(str(related))
         else:
             self.xml.addQuickElement("None")
         self.xml.endElement("field")
diff --git a/tests/regressiontests/serializers_regress/models.py b/tests/regressiontests/serializers_regress/models.py
index 999b79ccafc..3b9c228d4c6 100644
--- a/tests/regressiontests/serializers_regress/models.py
+++ b/tests/regressiontests/serializers_regress/models.py
@@ -129,6 +129,9 @@ class M2MSelfData(models.Model):
 class FKDataToField(models.Model):
     data = models.ForeignKey(UniqueAnchor, null=True, to_field='data')
 
+class FKDataToO2O(models.Model):
+    data = models.ForeignKey(O2OData, null=True)
+
 # The following test classes are for validating the
 # deserialization of objects that use a user-defined
 # field as the primary key.
diff --git a/tests/regressiontests/serializers_regress/tests.py b/tests/regressiontests/serializers_regress/tests.py
index 5df4c6818a1..dd724093aa0 100644
--- a/tests/regressiontests/serializers_regress/tests.py
+++ b/tests/regressiontests/serializers_regress/tests.py
@@ -197,6 +197,8 @@ The end."""),
     (fk_obj, 451, FKDataToField, "UAnchor 2"),
     (fk_obj, 452, FKDataToField, None),
 
+    (fk_obj, 460, FKDataToO2O, 300),
+
     (data_obj, 500, Anchor, "Anchor 3"),
     (data_obj, 501, Anchor, "Anchor 4"),
     (data_obj, 502, UniqueAnchor, "UAnchor 2"),