diff --git a/django/contrib/admin/options.py b/django/contrib/admin/options.py
index 2c2bcd5..1d3a150 100644
--- a/django/contrib/admin/options.py
+++ b/django/contrib/admin/options.py
@@ -73,7 +73,9 @@ class BaseModelAdmin(object):
     readonly_fields = ()
 
     def __init__(self):
-        self.formfield_overrides = dict(FORMFIELD_FOR_DBFIELD_DEFAULTS, **self.formfield_overrides)
+        overrides = FORMFIELD_FOR_DBFIELD_DEFAULTS.copy()
+        overrides.update(self.formfield_overrides)
+        self.formfield_overrides = overrides
 
     def formfield_for_dbfield(self, db_field, **kwargs):
         """
diff --git a/tests/modeltests/aggregation/models.py b/tests/modeltests/aggregation/models.py
index e5f0f5d..74e43b8 100644
--- a/tests/modeltests/aggregation/models.py
+++ b/tests/modeltests/aggregation/models.py
@@ -191,8 +191,8 @@ u'The Definitive Guide to Django: Web Development Done Right'
 
 # Calling values on a queryset that has annotations returns the output
 # as a dictionary
->>> Book.objects.filter(pk=1).annotate(mean_age=Avg('authors__age')).values()
-[{'rating': 4.5, 'isbn': u'159059725', 'name': u'The Definitive Guide to Django: Web Development Done Right', 'pubdate': datetime.date(2007, 12, 6), 'price': Decimal("30..."), 'contact_id': 1, 'id': 1, 'publisher_id': 1, 'pages': 447, 'mean_age': 34.5}]
+>>> [sorted(o.iteritems()) for o in Book.objects.filter(pk=1).annotate(mean_age=Avg('authors__age')).values()]
+[[('contact_id', 1), ('id', 1), ('isbn', u'159059725'), ('mean_age', 34.5), ('name', u'The Definitive Guide to Django: Web Development Done Right'), ('pages', 447), ('price', Decimal("30...")), ('pubdate', datetime.date(2007, 12, 6)), ('publisher_id', 1), ('rating', 4.5)]]
 
 >>> Book.objects.filter(pk=1).annotate(mean_age=Avg('authors__age')).values('pk', 'isbn', 'mean_age')
 [{'pk': 1, 'isbn': u'159059725', 'mean_age': 34.5}]
@@ -203,8 +203,8 @@ u'The Definitive Guide to Django: Web Development Done Right'
 
 # An empty values() call before annotating has the same effect as an
 # empty values() call after annotating
->>> Book.objects.filter(pk=1).values().annotate(mean_age=Avg('authors__age'))
-[{'rating': 4.5, 'isbn': u'159059725', 'name': u'The Definitive Guide to Django: Web Development Done Right', 'pubdate': datetime.date(2007, 12, 6), 'price': Decimal("30..."), 'contact_id': 1, 'id': 1, 'publisher_id': 1, 'pages': 447, 'mean_age': 34.5}]
+>>> [sorted(o.iteritems()) for o in Book.objects.filter(pk=1).values().annotate(mean_age=Avg('authors__age'))]
+[[('contact_id', 1), ('id', 1), ('isbn', u'159059725'), ('mean_age', 34.5), ('name', u'The Definitive Guide to Django: Web Development Done Right'), ('pages', 447), ('price', Decimal("30...")), ('pubdate', datetime.date(2007, 12, 6)), ('publisher_id', 1), ('rating', 4.5)]]
 
 # Calling annotate() on a ValuesQuerySet annotates over the groups of
 # fields to be selected by the ValuesQuerySet.
diff --git a/tests/modeltests/expressions/models.py b/tests/modeltests/expressions/models.py
index 76006e1..f6292f5 100644
--- a/tests/modeltests/expressions/models.py
+++ b/tests/modeltests/expressions/models.py
@@ -127,6 +127,6 @@ FieldError: Joined field references are not permitted in this query
 >>> acme.save()
 Traceback (most recent call last):
 ...
-TypeError: int() argument must be a string or a number...
+TypeError: ...
 
 """}
diff --git a/tests/regressiontests/aggregation_regress/models.py b/tests/regressiontests/aggregation_regress/models.py
index 7c51cd1..66a5ff7 100644
--- a/tests/regressiontests/aggregation_regress/models.py
+++ b/tests/regressiontests/aggregation_regress/models.py
@@ -174,8 +174,8 @@ FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, conta
 {'number': 1132, 'select': 1132}
 
 # Regression for #10064: select_related() plays nice with aggregates
->>> Book.objects.select_related('publisher').annotate(num_authors=Count('authors')).values()[0]
-{'rating': 4.0, 'isbn': u'013790395', 'name': u'Artificial Intelligence: A Modern Approach', 'pubdate': datetime.date(1995, 1, 15), 'price': Decimal("82.8..."), 'contact_id': 8, 'id': 5, 'num_authors': 2, 'publisher_id': 3, 'pages': 1132}
+>>> sorted(Book.objects.select_related('publisher').annotate(num_authors=Count('authors')).values()[0].iteritems())
+[('contact_id', 8), ('id', 5), ('isbn', u'013790395'), ('name', u'Artificial Intelligence: A Modern Approach'), ('num_authors', 2), ('pages', 1132), ('price', Decimal("82.8...")), ('pubdate', datetime.date(1995, 1, 15)), ('publisher_id', 3), ('rating', 4.0)]
 
 # Regression for #10010: exclude on an aggregate field is correctly negated
 >>> len(Book.objects.annotate(num_authors=Count('authors')))
@@ -219,8 +219,8 @@ FieldError: Cannot resolve keyword 'foo' into field. Choices are: authors, conta
 >>> Book.objects.filter(id__in=[]).aggregate(num_authors=Count('authors'), avg_authors=Avg('authors'), max_authors=Max('authors'), max_price=Max('price'), max_rating=Max('rating'))
 {'max_authors': None, 'max_rating': None, 'num_authors': 0, 'avg_authors': None, 'max_price': None}
 
->>> Publisher.objects.filter(pk=5).annotate(num_authors=Count('book__authors'), avg_authors=Avg('book__authors'), max_authors=Max('book__authors'), max_price=Max('book__price'), max_rating=Max('book__rating')).values()
-[{'max_authors': None, 'name': u"Jonno's House of Books", 'num_awards': 0, 'max_price': None, 'num_authors': 0, 'max_rating': None, 'id': 5, 'avg_authors': None}]
+>>> list(Publisher.objects.filter(pk=5).annotate(num_authors=Count('book__authors'), avg_authors=Avg('book__authors'), max_authors=Max('book__authors'), max_price=Max('book__price'), max_rating=Max('book__rating')).values()) == [{'max_authors': None, 'name': u"Jonno's House of Books", 'num_awards': 0, 'max_price': None, 'num_authors': 0, 'max_rating': None, 'id': 5, 'avg_authors': None}]
+True
 
 # Regression for #10113 - Fields mentioned in order_by() must be included in the GROUP BY.
 # This only becomes a problem when the order_by introduces a new join.
