diff --git a/wagtail/wagtailsearch/backends/base.py b/wagtail/wagtailsearch/backends/base.py
index e3a3a9bd2..29dc9161e 100644
--- a/wagtail/wagtailsearch/backends/base.py
+++ b/wagtail/wagtailsearch/backends/base.py
@@ -1,8 +1,7 @@
-from django.db import models
 from django.db.models.query import QuerySet
 from django.core.exceptions import ImproperlyConfigured
 
-from wagtail.wagtailsearch.index import Indexed
+from wagtail.wagtailsearch.index import class_is_indexed
 from wagtail.wagtailsearch.utils import normalise_query_string
 
 
@@ -10,13 +9,6 @@ class BaseSearch(object):
     def __init__(self, params):
         pass
 
-    def object_can_be_indexed(self, obj):
-        # Object must be a decendant of Indexed and be a django model
-        if not isinstance(obj, Indexed) or not isinstance(obj, models.Model):
-            return False
-
-        return True
-
     def reset_index(self):
         return NotImplemented
 
@@ -47,8 +39,8 @@ class BaseSearch(object):
             model = model_or_queryset
             queryset = model_or_queryset.objects.all()
 
-        # Model must be a descendant of Indexed and be a django model
-        if not issubclass(model, Indexed) or not issubclass(model, models.Model):
+        # Model must be a class that is in the index
+        if not class_is_indexed(model):
             return []
 
         # Normalise query string
diff --git a/wagtail/wagtailsearch/backends/elasticsearch.py b/wagtail/wagtailsearch/backends/elasticsearch.py
index ba6dc35a3..7a1eaf6f1 100644
--- a/wagtail/wagtailsearch/backends/elasticsearch.py
+++ b/wagtail/wagtailsearch/backends/elasticsearch.py
@@ -18,7 +18,7 @@ from elasticsearch import Elasticsearch, NotFoundError, RequestError
 from elasticsearch.helpers import bulk
 
 from wagtail.wagtailsearch.backends.base import BaseSearch
-from wagtail.wagtailsearch.index import Indexed, SearchField, FilterField
+from wagtail.wagtailsearch.index import Indexed, SearchField, FilterField, class_is_indexed
 
 
 class ElasticSearchMapping(object):
@@ -563,7 +563,7 @@ class ElasticSearch(BaseSearch):
 
     def add(self, obj):
         # Make sure the object can be indexed
-        if not self.object_can_be_indexed(obj):
+        if not class_is_indexed(obj.__class__):
             return
 
         # Get mapping
@@ -573,6 +573,9 @@ class ElasticSearch(BaseSearch):
         self.es.index(self.es_index, mapping.get_document_type(), mapping.get_document(obj), id=mapping.get_document_id(obj))
 
     def add_bulk(self, model, obj_list):
+        if not class_is_indexed(model):
+            return
+
         # Get mapping
         mapping = ElasticSearchMapping(model)
         doc_type = mapping.get_document_type()
@@ -580,10 +583,6 @@ class ElasticSearch(BaseSearch):
         # Create list of actions
         actions = []
         for obj in obj_list:
-            # Object must be a decendant of Indexed and be a django model
-            if not self.object_can_be_indexed(obj):
-                continue
-
             # Create the action
             action = {
                 '_index': self.es_index,
@@ -597,8 +596,8 @@ class ElasticSearch(BaseSearch):
         bulk(self.es, actions)
 
     def delete(self, obj):
-        # Object must be a decendant of Indexed and be a django model
-        if not isinstance(obj, Indexed) or not isinstance(obj, models.Model):
+        # Make sure the object can be indexed
+        if not class_is_indexed(obj.__class__):
             return
 
         # Get mapping
diff --git a/wagtail/wagtailsearch/index.py b/wagtail/wagtailsearch/index.py
index 169f48cb3..bbe9dbf6a 100644
--- a/wagtail/wagtailsearch/index.py
+++ b/wagtail/wagtailsearch/index.py
@@ -72,6 +72,17 @@ class Indexed(object):
     search_fields = ()
 
 
+def get_indexed_models():
+    return [
+        model for model in models.get_models()
+        if issubclass(model, Indexed) and not model._meta.abstract
+    ]
+
+
+def class_is_indexed(cls):
+    return issubclass(cls, Indexed) and issubclass(cls, models.Model) and not cls._meta.abstract
+
+
 class BaseField(object):
     suffix = ''
 
diff --git a/wagtail/wagtailsearch/management/commands/update_index.py b/wagtail/wagtailsearch/management/commands/update_index.py
index 86d854d9d..149a49f35 100644
--- a/wagtail/wagtailsearch/management/commands/update_index.py
+++ b/wagtail/wagtailsearch/management/commands/update_index.py
@@ -1,22 +1,18 @@
 from optparse import make_option
 
 from django.core.management.base import BaseCommand
-from django.db import models
 from django.conf import settings
 
-from wagtail.wagtailsearch.index import Indexed
+from wagtail.wagtailsearch.index import Indexed, get_indexed_models
 from wagtail.wagtailsearch.backends import get_search_backend
 
 
 class Command(BaseCommand):
     def get_object_list(self):
-        # Get list of indexed models
-        indexed_models = [model for model in models.get_models() if issubclass(model, Indexed)]
-
         # Return list of (model_name, queryset) tuples
         return [
             (model, model.get_indexed_objects())
-            for model in indexed_models
+            for model in get_indexed_models()
         ]
 
     def update_backend(self, backend_name, object_list):
diff --git a/wagtail/wagtailsearch/signal_handlers.py b/wagtail/wagtailsearch/signal_handlers.py
index c95510692..f471c1871 100644
--- a/wagtail/wagtailsearch/signal_handlers.py
+++ b/wagtail/wagtailsearch/signal_handlers.py
@@ -1,7 +1,6 @@
 from django.db.models.signals import post_save, post_delete
-from django.db import models
 
-from wagtail.wagtailsearch.index import Indexed
+from wagtail.wagtailsearch.index import Indexed, get_indexed_models
 from wagtail.wagtailsearch.backends import get_search_backends
 
 
@@ -34,10 +33,7 @@ def post_delete_signal_handler(instance, **kwargs):
 
 
 def register_signal_handlers():
-    # Get list of models that should be indexed
-    indexed_models = [model for model in models.get_models() if issubclass(model, Indexed)]
-
     # Loop through list and register signal handlers for each one
-    for model in indexed_models:
+    for model in get_indexed_models():
         post_save.connect(post_save_signal_handler, sender=model)
         post_delete.connect(post_delete_signal_handler, sender=model)