diff --git a/AUTHORS b/AUTHORS
index d085663500..e22ee45cbf 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -303,6 +303,7 @@ answer newbie questions, and generally made Django that much better:
     phil@produxion.net
     phil.h.smith@gmail.com
     Gustavo Picon
+    Michael Placentra II <someone@michaelplacentra2.net>
     Luke Plant <http://lukeplant.me.uk/>
     plisk
     Mihai Preda <mihai_preda@yahoo.com>
@@ -342,6 +343,7 @@ answer newbie questions, and generally made Django that much better:
     jason.sidabras@gmail.com
     Jozko Skrablin <jozko.skrablin@gmail.com>
     Ben Slavin <benjamin.slavin@gmail.com>
+    sloonz <simon.lipp@insa-lyon.fr>
     SmileyChris <smileychris@gmail.com>
     smurf@smurf.noris.de
     Vsevolod Solovyov
diff --git a/django/db/models/base.py b/django/db/models/base.py
index 51cefcf77b..36dd5ee5e6 100644
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -299,6 +299,12 @@ class Model(object):
         # attributes we have been given to the class we have been given.
         if not raw:
             for parent, field in meta.parents.items():
+                # At this point, parent's primary key field may be unknown
+                # (for example, from administration form which doesn't fill
+                # this field). If so, fill it.
+                if getattr(self, parent._meta.pk.attname) is None and getattr(self, field.attname) is not None:
+                    setattr(self, parent._meta.pk.attname, getattr(self, field.attname))
+
                 self.save_base(raw, parent)
                 setattr(self, field.attname, self._get_pk_val(parent._meta))
 
diff --git a/django/db/models/fields/related.py b/django/db/models/fields/related.py
index c76c87ec74..febe9884ed 100644
--- a/django/db/models/fields/related.py
+++ b/django/db/models/fields/related.py
@@ -706,6 +706,7 @@ class OneToOneField(ForeignKey):
     """
     def __init__(self, to, to_field=None, **kwargs):
         kwargs['unique'] = True
+        kwargs['editable'] = False
         if 'num_in_admin' not in kwargs:
             kwargs['num_in_admin'] = 0
         super(OneToOneField, self).__init__(to, to_field, OneToOneRel, **kwargs)
diff --git a/tests/regressiontests/model_inheritance_regress/models.py b/tests/regressiontests/model_inheritance_regress/models.py
index b78b493e15..3f4fa04b77 100644
--- a/tests/regressiontests/model_inheritance_regress/models.py
+++ b/tests/regressiontests/model_inheritance_regress/models.py
@@ -159,4 +159,19 @@ Traceback (most recent call last):
 ...
 DoesNotExist: ItalianRestaurant matching query does not exist.
 
+# Regression test for #6755
+>>> r = Restaurant(serves_pizza=False)
+>>> r.save()
+>>> r.id
+3
+>>> r.place_ptr_id
+3
+>>> r = Restaurant(place_ptr_id=3, serves_pizza=True)
+>>> r.save()
+>>> r.id
+3
+>>> r.place_ptr_id
+3
+
+
 """}