diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index c8447c7d9..a202d5973 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -17,6 +17,7 @@ Changelog
  * Fix: Default text of page links in rich text uses the public page title rather than the admin display title (Andy Chosak)
  * Fix: Specific page permission checks are now enforced when viewing a page revision (Andy Chosak)
  * Fix: `pageurl` and `slugurl` tags no longer fail when `request.site` is `None` (Samir Shah)
+ * Fix: Output form media on add/edit image forms with custom models (Matt Westcott)
 
 
 2.6.1 (05.08.2019)
diff --git a/docs/releases/2.7.rst b/docs/releases/2.7.rst
index fdaede9b5..e312e6fc2 100644
--- a/docs/releases/2.7.rst
+++ b/docs/releases/2.7.rst
@@ -35,6 +35,7 @@ Bug fixes
  * Default text of page links in rich text uses the public page title rather than the admin display title (Andy Chosak)
  * Specific page permission checks are now enforced when viewing a page revision (Andy Chosak)
  * ``pageurl`` and ``slugurl`` tags no longer fail when ``request.site`` is ``None`` (Samir Shah)
+ * Output form media on add/edit image forms with custom models (Matt Westcott)
 
 
 Upgrade considerations
diff --git a/wagtail/images/templates/wagtailimages/chooser/chooser.html b/wagtail/images/templates/wagtailimages/chooser/chooser.html
index d60ddd72f..ca80787a9 100644
--- a/wagtail/images/templates/wagtailimages/chooser/chooser.html
+++ b/wagtail/images/templates/wagtailimages/chooser/chooser.html
@@ -3,6 +3,9 @@
 {% trans "Choose an image" as choose_str %}
 {% include "wagtailadmin/shared/header.html" with title=choose_str merged=1 tabbed=1 icon="image" %}
 
+{{ uploadform.media.js }}
+{{ uploadform.media.css }}
+
 {% if uploadform %}
     <ul class="tab-nav merged">
         <li class="{% if not uploadform.errors %}active{% endif %}"><a href="#search" >{% trans "Search" %}</a></li>
diff --git a/wagtail/images/templates/wagtailimages/images/add.html b/wagtail/images/templates/wagtailimages/images/add.html
index 0ca1a23b0..b074c91e5 100644
--- a/wagtail/images/templates/wagtailimages/images/add.html
+++ b/wagtail/images/templates/wagtailimages/images/add.html
@@ -6,6 +6,8 @@
 {% block extra_js %}
     {{ block.super }}
 
+    {{ form.media.js }}
+
     {% url 'wagtailadmin_tag_autocomplete' as autocomplete_url %}
     <script>
         $(function() {
@@ -16,6 +18,11 @@
     </script>
 {% endblock %}
 
+{% block extra_css %}
+    {{ block.super }}
+    {{ form.media.css }}
+{% endblock %}
+
 {% block content %}
     {% trans "Add image" as add_str %}
     {% include "wagtailadmin/shared/header.html" with title=add_str icon="image" %}
diff --git a/wagtail/images/templates/wagtailimages/images/edit.html b/wagtail/images/templates/wagtailimages/images/edit.html
index c2927f354..c0aa5aff2 100644
--- a/wagtail/images/templates/wagtailimages/images/edit.html
+++ b/wagtail/images/templates/wagtailimages/images/edit.html
@@ -4,6 +4,8 @@
 {% block extra_css %}
     {{ block.super }}
 
+    {{ form.media.css }}
+
     <!-- Focal point chooser -->
     <link rel="stylesheet" href="{% static 'wagtailimages/css/vendor/jquery.Jcrop.min.css' %}" type="text/css">
     <link rel="stylesheet" href="{% static 'wagtailimages/css/focal-point-chooser.css' %}" type="text/css">
@@ -12,6 +14,8 @@
 {% block extra_js %}
     {{ block.super }}
 
+    {{ form.media.js }}
+
     {% url 'wagtailadmin_tag_autocomplete' as autocomplete_url %}
     <script>
         $(function() {
diff --git a/wagtail/images/templates/wagtailimages/multiple/add.html b/wagtail/images/templates/wagtailimages/multiple/add.html
index 3a8e3719c..91bb0fd32 100644
--- a/wagtail/images/templates/wagtailimages/multiple/add.html
+++ b/wagtail/images/templates/wagtailimages/multiple/add.html
@@ -7,6 +7,8 @@
 {% block extra_css %}
     {{ block.super }}
 
+    {{ form_media.css }}
+
     <link rel="stylesheet" href="{% static 'wagtailimages/css/add-multiple.css' %}" type="text/css" />
 {% endblock %}
 
@@ -75,6 +77,8 @@
 {% block extra_js %}
     {{ block.super }}
 
+    {{ form_media.js }}
+
     <!-- this exact order of plugins is vital -->
     <script src="{% static 'wagtailimages/js/vendor/load-image.min.js' %}"></script>
     <script src="{% static 'wagtailimages/js/vendor/canvas-to-blob.min.js' %}"></script>
diff --git a/wagtail/images/tests/test_admin_views.py b/wagtail/images/tests/test_admin_views.py
index ef3ead9f5..1248339c0 100644
--- a/wagtail/images/tests/test_admin_views.py
+++ b/wagtail/images/tests/test_admin_views.py
@@ -10,6 +10,7 @@ from django.utils.http import RFC3986_SUBDELIMS, urlquote
 
 from wagtail.core.models import Collection, GroupCollectionPermission
 from wagtail.images.views.serve import generate_signature
+from wagtail.tests.testapp.models import CustomImage
 from wagtail.tests.utils import WagtailTestUtils
 
 from .utils import Image, get_test_image_file
@@ -108,6 +109,9 @@ class TestImageAddView(TestCase, WagtailTestUtils):
         # Ensure the form supports file uploads
         self.assertContains(response, 'enctype="multipart/form-data"')
 
+        # draftail should NOT be a standard JS include on this page
+        self.assertNotContains(response, 'wagtailadmin/js/draftail.js')
+
     def test_get_with_collections(self):
         root_collection = Collection.get_first_root_node()
         root_collection.add_child(name="Evil plans")
@@ -119,6 +123,21 @@ class TestImageAddView(TestCase, WagtailTestUtils):
         self.assertContains(response, '<label for="id_collection">')
         self.assertContains(response, "Evil plans")
 
+    @override_settings(WAGTAILIMAGES_IMAGE_MODEL='tests.CustomImage')
+    def test_get_with_custom_image_model(self):
+        response = self.get()
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(response, 'wagtailimages/images/add.html')
+
+        # Ensure the form supports file uploads
+        self.assertContains(response, 'enctype="multipart/form-data"')
+
+        # custom fields should be included
+        self.assertContains(response, 'name="fancy_caption"')
+
+        # form media should be imported
+        self.assertContains(response, 'wagtailadmin/js/draftail.js')
+
     def test_add(self):
         response = self.post({
             'title': "Test image",
@@ -325,6 +344,11 @@ class TestImageEditView(TestCase, WagtailTestUtils):
         # Ensure the form supports file uploads
         self.assertContains(response, 'enctype="multipart/form-data"')
 
+        # draftail should NOT be a standard JS include on this page
+        # (see TestImageEditViewWithCustomImageModel - this confirms that form media
+        # definitions are being respected)
+        self.assertNotContains(response, 'wagtailadmin/js/draftail.js')
+
     @override_settings(WAGTAIL_USAGE_COUNT_ENABLED=True)
     def test_with_usage_count(self):
         response = self.get()
@@ -514,6 +538,34 @@ class TestImageEditView(TestCase, WagtailTestUtils):
         self.assertContains(response, 'data-original-width="1024"')
 
 
+@override_settings(WAGTAILIMAGES_IMAGE_MODEL='tests.CustomImage')
+class TestImageEditViewWithCustomImageModel(TestCase, WagtailTestUtils):
+    def setUp(self):
+        self.login()
+
+        # Create an image to edit
+        self.image = CustomImage.objects.create(
+            title="Test image",
+            file=get_test_image_file(),
+        )
+
+        self.storage = self.image.file.storage
+
+    def get(self, params={}):
+        return self.client.get(reverse('wagtailimages:edit', args=(self.image.id,)), params)
+
+    def test_get_with_custom_image_model(self):
+        response = self.get()
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(response, 'wagtailimages/images/edit.html')
+
+        # Ensure the form supports file uploads
+        self.assertContains(response, 'enctype="multipart/form-data"')
+
+        # form media should be imported
+        self.assertContains(response, 'wagtailadmin/js/draftail.js')
+
+
 class TestImageDeleteView(TestCase, WagtailTestUtils):
     def setUp(self):
         self.login()
@@ -571,6 +623,23 @@ class TestImageChooserView(TestCase, WagtailTestUtils):
         self.assertEqual(response_json['step'], 'chooser')
         self.assertTemplateUsed(response, 'wagtailimages/chooser/chooser.html')
 
+        # draftail should NOT be a standard JS include on this page
+        self.assertNotIn('wagtailadmin/js/draftail.js', response_json['html'])
+
+    @override_settings(WAGTAILIMAGES_IMAGE_MODEL='tests.CustomImage')
+    def test_with_custom_image_model(self):
+        response = self.get()
+        self.assertEqual(response.status_code, 200)
+        response_json = json.loads(response.content.decode())
+        self.assertEqual(response_json['step'], 'chooser')
+        self.assertTemplateUsed(response, 'wagtailimages/chooser/chooser.html')
+
+        # custom form fields should be present
+        self.assertIn('name="image-chooser-upload-fancy_caption"', response_json['html'])
+
+        # form media imports should appear on the page
+        self.assertIn('wagtailadmin/js/draftail.js', response_json['html'])
+
     def test_search(self):
         response = self.get({'q': "Hello"})
         self.assertEqual(response.status_code, 200)
@@ -898,6 +967,11 @@ class TestMultipleImageUploader(TestCase, WagtailTestUtils):
         self.assertEqual(response.status_code, 200)
         self.assertTemplateUsed(response, 'wagtailimages/multiple/add.html')
 
+        # draftail should NOT be a standard JS include on this page
+        # (see TestMultipleImageUploaderWithCustomImageModel - this confirms that form media
+        # definitions are being respected)
+        self.assertNotContains(response, 'wagtailadmin/js/draftail.js')
+
     @override_settings(WAGTAILIMAGES_MAX_UPLOAD_SIZE=1000)
     def test_add_max_file_size_context_variables(self):
         response = self.client.get(reverse('wagtailimages:add_multiple'))
@@ -1095,6 +1169,123 @@ class TestMultipleImageUploader(TestCase, WagtailTestUtils):
         self.assertEqual(response.status_code, 400)
 
 
+@override_settings(WAGTAILIMAGES_IMAGE_MODEL='tests.CustomImage')
+class TestMultipleImageUploaderWithCustomImageModel(TestCase, WagtailTestUtils):
+    """
+    This tests the multiple image upload views located in wagtailimages/views/multiple.py
+    with a custom image model
+    """
+    def setUp(self):
+        self.login()
+
+        # Create an image for running tests on
+        self.image = CustomImage.objects.create(
+            title="Test image",
+            file=get_test_image_file(),
+        )
+
+    def test_add(self):
+        """
+        This tests that the add view responds correctly on a GET request
+        """
+        # Send request
+        response = self.client.get(reverse('wagtailimages:add_multiple'))
+
+        # Check response
+        self.assertEqual(response.status_code, 200)
+        self.assertTemplateUsed(response, 'wagtailimages/multiple/add.html')
+
+        # response should include form media for the image edit form
+        self.assertContains(response, 'wagtailadmin/js/draftail.js')
+
+    def test_add_post(self):
+        """
+        This tests that a POST request to the add view saves the image and returns an edit form
+        """
+        response = self.client.post(reverse('wagtailimages:add_multiple'), {
+            'files[]': SimpleUploadedFile('test.png', get_test_image_file().file.getvalue()),
+        }, HTTP_X_REQUESTED_WITH='XMLHttpRequest')
+
+        # Check response
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response['Content-Type'], 'application/json')
+        self.assertTemplateUsed(response, 'wagtailimages/multiple/edit_form.html')
+
+        # Check image
+        self.assertIn('image', response.context)
+        self.assertEqual(response.context['image'].title, 'test.png')
+        self.assertTrue(response.context['image'].file_size)
+        self.assertTrue(response.context['image'].file_hash)
+
+        # Check form
+        self.assertIn('form', response.context)
+        self.assertEqual(response.context['form'].initial['title'], 'test.png')
+        self.assertIn('caption', response.context['form'].fields)
+        self.assertNotIn('not_editable_field', response.context['form'].fields)
+
+        # Check JSON
+        response_json = json.loads(response.content.decode())
+        self.assertIn('image_id', response_json)
+        self.assertIn('form', response_json)
+        self.assertIn('success', response_json)
+        self.assertEqual(response_json['image_id'], response.context['image'].id)
+        self.assertTrue(response_json['success'])
+
+    def test_edit_post(self):
+        """
+        This tests that a POST request to the edit view edits the image
+        """
+        # Send request
+        response = self.client.post(reverse('wagtailimages:edit_multiple', args=(self.image.id, )), {
+            ('image-%d-title' % self.image.id): "New title!",
+            ('image-%d-tags' % self.image.id): "",
+            ('image-%d-caption' % self.image.id): "a boot stamping on a human face, forever",
+        }, HTTP_X_REQUESTED_WITH='XMLHttpRequest')
+
+        # Check response
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response['Content-Type'], 'application/json')
+
+        # Check JSON
+        response_json = json.loads(response.content.decode())
+        self.assertIn('image_id', response_json)
+        self.assertNotIn('form', response_json)
+        self.assertIn('success', response_json)
+        self.assertEqual(response_json['image_id'], self.image.id)
+        self.assertTrue(response_json['success'])
+
+        # check that image has been updated
+        new_image = CustomImage.objects.get(id=self.image.id)
+        self.assertEqual(new_image.title, "New title!")
+        self.assertEqual(new_image.caption, "a boot stamping on a human face, forever")
+
+    def test_delete_post(self):
+        """
+        This tests that a POST request to the delete view deletes the image
+        """
+        # Send request
+        response = self.client.post(reverse(
+            'wagtailimages:delete_multiple', args=(self.image.id, )
+        ), HTTP_X_REQUESTED_WITH='XMLHttpRequest')
+
+        # Check response
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response['Content-Type'], 'application/json')
+
+        # Make sure the image is deleted
+        self.assertFalse(Image.objects.filter(id=self.image.id).exists())
+
+        # Check JSON
+        response_json = json.loads(response.content.decode())
+        self.assertIn('image_id', response_json)
+        self.assertIn('success', response_json)
+        self.assertEqual(response_json['image_id'], self.image.id)
+        self.assertTrue(response_json['success'])
+
+        # check that image has been deleted
+        self.assertEqual(CustomImage.objects.filter(id=self.image.id).count(), 0)
+
+
 class TestURLGeneratorView(TestCase, WagtailTestUtils):
     def setUp(self):
         # Create an image for running tests on
diff --git a/wagtail/images/tests/tests.py b/wagtail/images/tests/tests.py
index 7e0462886..b0a5c433c 100644
--- a/wagtail/images/tests/tests.py
+++ b/wagtail/images/tests/tests.py
@@ -569,6 +569,7 @@ class TestGetImageForm(TestCase, WagtailTestUtils):
             'focal_point_width',
             'focal_point_height',
             'caption',
+            'fancy_caption',
         ])
 
     def test_file_field(self):
diff --git a/wagtail/images/views/multiple.py b/wagtail/images/views/multiple.py
index bd2740f16..01f6b89a5 100644
--- a/wagtail/images/views/multiple.py
+++ b/wagtail/images/views/multiple.py
@@ -93,16 +93,19 @@ def add(request):
                 'error_message': '\n'.join(['\n'.join([force_text(i) for i in v]) for k, v in form.errors.items()]),
             })
     else:
+        # Instantiate a dummy copy of the form that we can retrieve validation messages and media from;
+        # actual rendering of forms will happen on AJAX POST rather than here
         form = ImageForm(user=request.user)
 
-    return render(request, 'wagtailimages/multiple/add.html', {
-        'max_filesize': form.fields['file'].max_upload_size,
-        'help_text': form.fields['file'].help_text,
-        'allowed_extensions': ALLOWED_EXTENSIONS,
-        'error_max_file_size': form.fields['file'].error_messages['file_too_large_unknown_size'],
-        'error_accepted_file_types': form.fields['file'].error_messages['invalid_image'],
-        'collections': collections_to_choose,
-    })
+        return render(request, 'wagtailimages/multiple/add.html', {
+            'max_filesize': form.fields['file'].max_upload_size,
+            'help_text': form.fields['file'].help_text,
+            'allowed_extensions': ALLOWED_EXTENSIONS,
+            'error_max_file_size': form.fields['file'].error_messages['file_too_large_unknown_size'],
+            'error_accepted_file_types': form.fields['file'].error_messages['invalid_image'],
+            'collections': collections_to_choose,
+            'form_media': form.media,
+        })
 
 
 @require_POST
diff --git a/wagtail/tests/testapp/migrations/0001_initial.py b/wagtail/tests/testapp/migrations/0001_initial.py
index 032928e6e..192eb0170 100644
--- a/wagtail/tests/testapp/migrations/0001_initial.py
+++ b/wagtail/tests/testapp/migrations/0001_initial.py
@@ -135,8 +135,9 @@ class Migration(migrations.Migration):
                 ('focal_point_width', models.PositiveIntegerField(blank=True, null=True)),
                 ('focal_point_height', models.PositiveIntegerField(blank=True, null=True)),
                 ('file_size', models.PositiveIntegerField(editable=False, null=True)),
-                ('caption', models.CharField(max_length=255)),
-                ('not_editable_field', models.CharField(max_length=255)),
+                ('caption', models.CharField(max_length=255, blank=True)),
+                ('fancy_caption', wagtail.core.fields.RichTextField(blank=True)),
+                ('not_editable_field', models.CharField(max_length=255, blank=True)),
                 ('tags', taggit.managers.TaggableManager(blank=True, help_text=None, through='taggit.TaggedItem', to='taggit.Tag', verbose_name='tags')),
                 ('uploaded_by_user', models.ForeignKey(blank=True, editable=False, null=True, on_delete=django.db.models.deletion.SET_NULL, to=settings.AUTH_USER_MODEL, verbose_name='uploaded by user')),
             ],
diff --git a/wagtail/tests/testapp/models.py b/wagtail/tests/testapp/models.py
index a659113fa..ec3cffab2 100644
--- a/wagtail/tests/testapp/models.py
+++ b/wagtail/tests/testapp/models.py
@@ -899,11 +899,13 @@ class SnippetChooserModelWithCustomPrimaryKey(models.Model):
 
 
 class CustomImage(AbstractImage):
-    caption = models.CharField(max_length=255)
-    not_editable_field = models.CharField(max_length=255)
+    caption = models.CharField(max_length=255, blank=True)
+    fancy_caption = RichTextField(blank=True)
+    not_editable_field = models.CharField(max_length=255, blank=True)
 
     admin_form_fields = Image.admin_form_fields + (
         'caption',
+        'fancy_caption',
     )