diff --git a/django/contrib/comments/forms.py b/django/contrib/comments/forms.py
index adb2741873..58af4466d0 100644
--- a/django/contrib/comments/forms.py
+++ b/django/contrib/comments/forms.py
@@ -8,6 +8,7 @@ from django.conf import settings
 from django.http import Http404
 from django.contrib.contenttypes.models import ContentType
 from models import Comment
+from django.utils.encoding import force_unicode
 from django.utils.text import get_text_list
 from django.utils.translation import ngettext
 from django.utils.translation import ugettext_lazy as _
@@ -49,7 +50,7 @@ class CommentForm(forms.Form):
 
         new = Comment(
             content_type = ContentType.objects.get_for_model(self.target_object),
-            object_pk    = str(self.target_object._get_pk_val()),
+            object_pk    = force_unicode(self.target_object._get_pk_val()),
             user_name    = self.cleaned_data["name"],
             user_email   = self.cleaned_data["email"],
             user_url     = self.cleaned_data["url"],
diff --git a/django/contrib/comments/managers.py b/django/contrib/comments/managers.py
index d664fdaca0..a1ac8097da 100644
--- a/django/contrib/comments/managers.py
+++ b/django/contrib/comments/managers.py
@@ -1,6 +1,7 @@
 from django.db import models
 from django.dispatch import dispatcher
 from django.contrib.contenttypes.models import ContentType
+from django.utils.encoding import force_unicode
 
 class CommentManager(models.Manager):
 
@@ -18,5 +19,5 @@ class CommentManager(models.Manager):
         ct = ContentType.objects.get_for_model(model)
         qs = self.get_query_set().filter(content_type=ct)
         if isinstance(model, models.Model):
-            qs = qs.filter(object_pk=model._get_pk_val())
+            qs = qs.filter(object_pk=force_unicode(model._get_pk_val()))
         return qs