diff --git a/django/contrib/admin/helpers.py b/django/contrib/admin/helpers.py
index 3c1febd26b..b969653317 100644
--- a/django/contrib/admin/helpers.py
+++ b/django/contrib/admin/helpers.py
@@ -154,7 +154,7 @@ class AdminReadonlyField(object):
         field, obj, model_admin = self.field, self.form.instance, self.model_admin
         try:
             f, attr, value = lookup_field(field, obj, model_admin)
-        except (AttributeError, ObjectDoesNotExist):
+        except (AttributeError, ValueError, ObjectDoesNotExist):
             result_repr = EMPTY_CHANGELIST_VALUE
         else:
             if f is None:
diff --git a/tests/regressiontests/admin_views/models.py b/tests/regressiontests/admin_views/models.py
index fffc40571e..e66e65fa85 100644
--- a/tests/regressiontests/admin_views/models.py
+++ b/tests/regressiontests/admin_views/models.py
@@ -565,6 +565,16 @@ class CyclicTwo(models.Model):
     def __unicode__(self):
         return self.name
 
+class Topping(models.Model):
+    name = models.CharField(max_length=20) 
+
+class Pizza(models.Model):
+    name = models.CharField(max_length=20)
+    toppings = models.ManyToManyField('Topping')
+
+class PizzaAdmin(admin.ModelAdmin):
+    readonly_fields = ('toppings',)
+
 admin.site.register(Article, ArticleAdmin)
 admin.site.register(CustomArticle, CustomArticleAdmin)
 admin.site.register(Section, save_as=True, inlines=[ArticleInline])
@@ -609,3 +619,5 @@ admin.site.register(CyclicTwo)
 admin.site.register(Book, inlines=[ChapterInline])
 admin.site.register(Promo)
 admin.site.register(ChapterXtra1)
+admin.site.register(Pizza, PizzaAdmin)
+admin.site.register(Topping)
diff --git a/tests/regressiontests/admin_views/tests.py b/tests/regressiontests/admin_views/tests.py
index 280a89d41e..3414ea0646 100644
--- a/tests/regressiontests/admin_views/tests.py
+++ b/tests/regressiontests/admin_views/tests.py
@@ -1986,6 +1986,11 @@ class ReadonlyTest(TestCase):
         p = Post.objects.order_by('-id')[0]
         self.assertEqual(p.posted, datetime.date.today())
 
+    def test_readonly_manytomany(self):
+        "Regression test for #13004"
+        response = self.client.get('/test_admin/admin/admin_views/pizza/add/')
+        self.assertEqual(response.status_code, 200)
+
 class IncompleteFormTest(TestCase):
     """
     Tests validation of a ModelForm that doesn't explicitly have all data