diff --git a/boards/models.py b/boards/models.py
--- a/boards/models.py
+++ b/boards/models.py
@@ -211,8 +211,8 @@ class Post(models.Model):
     text = MarkupField(default_markup_type=DEFAULT_MARKUP_TYPE,
                        escape_html=False)
 
-    image_width = models.IntegerField()
-    image_height = models.IntegerField()
+    image_width = models.IntegerField(default=0)
+    image_height = models.IntegerField(default=0)
 
     image = thumbs.ImageWithThumbsField(upload_to=_update_image_filename,
                                         blank=True, sizes=(IMAGE_THUMB_SIZE,),