diff --git a/wagtail/wagtailsearch/tests/test_related_fields.py b/wagtail/wagtailsearch/tests/test_related_fields.py
new file mode 100644
index 0000000000..057b01ef95
--- /dev/null
+++ b/wagtail/wagtailsearch/tests/test_related_fields.py
@@ -0,0 +1,92 @@
+import unittest
+
+import django
+from django.test import TestCase
+
+from wagtail.wagtailsearch import index
+from wagtail.tests.search.models import SearchTest, SearchTestChild
+from wagtail.tests.testapp.models import ManyToManyBlogPage, Advert
+
+
+class TestSelectOnQuerySet(TestCase):
+    def test_select_on_queryset_with_foreign_key(self):
+        fields = index.RelatedFields('page', [
+            index.SearchField('title'),
+        ])
+
+        queryset = fields.select_on_queryset(SearchTestChild.objects.all())
+
+        # ForeignKey should be select_related
+        self.assertFalse(queryset._prefetch_related_lookups)
+        self.assertIn('page', queryset.query.select_related)
+
+    def test_select_on_queryset_with_one_to_one(self):
+        fields = index.RelatedFields('searchtest_ptr', [
+            index.SearchField('title'),
+        ])
+
+        queryset = fields.select_on_queryset(SearchTestChild.objects.all())
+
+        # OneToOneField should be select_related
+        self.assertFalse(queryset._prefetch_related_lookups)
+        self.assertIn('searchtest_ptr', queryset.query.select_related)
+
+    def test_select_on_queryset_with_many_to_many(self):
+        fields = index.RelatedFields('adverts', [
+            index.SearchField('title'),
+        ])
+
+        queryset = fields.select_on_queryset(ManyToManyBlogPage.objects.all())
+
+        # ManyToManyField should be prefetch_related
+        self.assertIn('adverts', queryset._prefetch_related_lookups)
+        self.assertFalse(queryset.query.select_related)
+
+    @unittest.skipIf(django.VERSION < (1, 8), "Reverse relations not supported on Django 1.7")
+    def test_select_on_queryset_with_reverse_foreign_key(self):
+        fields = index.RelatedFields('categories', [
+            index.RelatedFields('category', [
+                index.SearchField('name')
+            ])
+        ])
+
+        queryset = fields.select_on_queryset(ManyToManyBlogPage.objects.all())
+
+        # reverse ForeignKey should be prefetch_related
+        self.assertIn('categories', queryset._prefetch_related_lookups)
+        self.assertFalse(queryset.query.select_related)
+
+    @unittest.skipIf(django.VERSION < (1, 8), "Reverse relations not supported on Django 1.7")
+    def test_select_on_queryset_with_reverse_one_to_one(self):
+        fields = index.RelatedFields('searchtestchild', [
+            index.SearchField('subtitle'),
+        ])
+
+        queryset = fields.select_on_queryset(SearchTest.objects.all())
+
+        # reverse OneToOneField should be select_related
+        self.assertFalse(queryset._prefetch_related_lookups)
+        self.assertIn('searchtestchild', queryset.query.select_related)
+
+    @unittest.skipIf(django.VERSION < (1, 8), "Reverse relations not supported on Django 1.7")
+    def test_select_on_queryset_with_reverse_many_to_many(self):
+        fields = index.RelatedFields('manytomanyblogpage', [
+            index.SearchField('title'),
+        ])
+
+        queryset = fields.select_on_queryset(Advert.objects.all())
+
+        # reverse ManyToManyField should be prefetch_related
+        self.assertIn('manytomanyblogpage', queryset._prefetch_related_lookups)
+        self.assertFalse(queryset.query.select_related)
+
+    def test_select_on_queryset_with_taggable_manager(self):
+        fields = index.RelatedFields('tags', [
+            index.SearchField('name'),
+        ])
+
+        queryset = fields.select_on_queryset(SearchTestChild.objects.all())
+
+        # Tags should be prefetch_related
+        self.assertIn('tags', queryset._prefetch_related_lookups)
+        self.assertFalse(queryset.query.select_related)