diff --git a/moto/backends.py b/moto/backends.py
index e07565497..ed237401a 100644
--- a/moto/backends.py
+++ b/moto/backends.py
@@ -25,3 +25,10 @@ BACKENDS = {
     'sts': sts_backend,
     'route53': route53_backend
 }
+
+
+def get_model(name):
+    for backend in BACKENDS.values():
+        models = getattr(backend.__class__, '__models__', {})
+        if name in models:
+            return getattr(backend, models[name])()
diff --git a/moto/core/models.py b/moto/core/models.py
index c5c23d155..fe0161f8d 100644
--- a/moto/core/models.py
+++ b/moto/core/models.py
@@ -65,8 +65,28 @@ class MockAWS(object):
         return wrapper
 
 
-class BaseBackend(object):
+class Model(type):
+    def __new__(self, clsname, bases, namespace):
+        cls = super(Model, self).__new__(self, clsname, bases, namespace)
+        cls.__models__ = {}
+        for name, value in namespace.iteritems():
+            model = getattr(value, "__returns_model__", False)
+            if model is not False:
+                cls.__models__[model] = name
+        for base in bases:
+            cls.__models__.update(getattr(base, "__models__", {}))
+        return cls
 
+    @staticmethod
+    def prop(model_name):
+        """ decorator to mark a class method as returning model values """
+        def dec(f):
+            f.__returns_model__ = model_name
+            return f
+        return dec
+
+
+class BaseBackend(object):
     def reset(self):
         self.__dict__ = {}
         self.__init__()
diff --git a/moto/ec2/models.py b/moto/ec2/models.py
index c25f49e28..3e384288d 100644
--- a/moto/ec2/models.py
+++ b/moto/ec2/models.py
@@ -3,8 +3,11 @@ import itertools
 from collections import defaultdict
 
 from boto.ec2.instance import Instance as BotoInstance, Reservation
+from boto.ec2.spotinstancerequest import SpotInstanceRequest as BotoSpotRequest
+from boto.ec2.launchspecification import LaunchSpecification
 
 from moto.core import BaseBackend
+from moto.core.models import Model
 from .exceptions import (
     InvalidIdError,
     DependencyViolationError,
@@ -937,42 +940,46 @@ class VPCGatewayAttachmentBackend(object):
         return attachment
 
 
-class SpotInstanceRequest(object):
+class SpotInstanceRequest(BotoSpotRequest):
     def __init__(self, spot_request_id, price, image_id, type, valid_from,
                  valid_until, launch_group, availability_zone_group, key_name,
                  security_groups, user_data, instance_type, placement, kernel_id,
-                 ramdisk_id, monitoring_enabled, subnet_id):
+                 ramdisk_id, monitoring_enabled, subnet_id, **kwargs):
+        super(SpotInstanceRequest, self).__init__(**kwargs)
+        ls = LaunchSpecification()
+        self.launch_specification = ls
         self.id = spot_request_id
         self.state = "open"
         self.price = price
-        self.image_id = image_id
         self.type = type
         self.valid_from = valid_from
         self.valid_until = valid_until
         self.launch_group = launch_group
         self.availability_zone_group = availability_zone_group
-        self.key_name = key_name
-        self.user_data = user_data
-        self.instance_type = instance_type
-        self.placement = placement
-        self.kernel_id = kernel_id
-        self.ramdisk_id = ramdisk_id
-        self.monitoring_enabled = monitoring_enabled
-        self.subnet_id = subnet_id
+        self.user_data = user_data  # NOT
+        ls.kernel = kernel_id
+        ls.ramdisk = ramdisk_id
+        ls.image_id = image_id
+        ls.key_name = key_name
+        ls.instance_type = instance_type
+        ls.placement = placement
+        ls.monitored = monitoring_enabled
+        ls.subnet_id = subnet_id
 
-        self.security_groups = []
         if security_groups:
             for group_name in security_groups:
                 group = ec2_backend.get_security_group_from_name(group_name)
                 if group:
-                    self.security_groups.append(group)
+                    ls.groups.append(group)
         else:
             # If not security groups, add the default
             default_group = ec2_backend.get_security_group_from_name("default")
-            self.security_groups.append(default_group)
+            ls.groups.append(default_group)
 
 
 class SpotRequestBackend(object):
+    __metaclass__ = Model
+
     def __init__(self):
         self.spot_instance_requests = {}
         super(SpotRequestBackend, self).__init__()
@@ -995,6 +1002,7 @@ class SpotRequestBackend(object):
             requests.append(request)
         return requests
 
+    @Model.prop('SpotInstanceRequest')
     def describe_spot_instance_requests(self):
         return self.spot_instance_requests.values()
 
diff --git a/moto/ec2/responses/spot_instances.py b/moto/ec2/responses/spot_instances.py
index 5ce8ee122..c05077407 100644
--- a/moto/ec2/responses/spot_instances.py
+++ b/moto/ec2/responses/spot_instances.py
@@ -95,27 +95,27 @@ REQUEST_SPOT_INSTANCES_TEMPLATE = """<RequestSpotInstancesResponse xmlns="http:/
       </status>
       <availabilityZoneGroup>{{ request.availability_zone_group }}</availabilityZoneGroup>
       <launchSpecification>
-        <imageId>{{ request.image_id }}</imageId>
-        <keyName>{{ request.key_name }}</keyName>
+        <imageId>{{ request.launch_specification.image_id }}</imageId>
+        <keyName>{{ request.launch_specification.key_name }}</keyName>
         <groupSet>
-          {% for group in request.security_groups %}
+          {% for group in request.launch_specification.groups %}
           <item>
             <groupId>{{ group.id }}</groupId>
             <groupName>{{ group.name }}</groupName>
           </item>
           {% endfor %}
         </groupSet>
-        <kernelId>{{ request.kernel_id }}</kernelId>
-        <ramdiskId>{{ request.ramdisk_id }}</ramdiskId>
-        <subnetId>{{ request.subnet_id }}</subnetId>
-        <instanceType>{{ request.instance_type }}</instanceType>
+        <kernelId>{{ request.launch_specification.kernel }}</kernelId>
+        <ramdiskId>{{ request.launch_specification.ramdisk }}</ramdiskId>
+        <subnetId>{{ request.launch_specification.subnet_id }}</subnetId>
+        <instanceType>{{ request.launch_specification.instance_type }}</instanceType>
         <blockDeviceMapping/>
         <monitoring>
-          <enabled>{{ request.monitoring_enabled }}</enabled>
+          <enabled>{{ request.launch_specification.monitored }}</enabled>
         </monitoring>
-        <ebsOptimized>{{ request.ebs_optimized }}</ebsOptimized>
+        <ebsOptimized>{{ request.launch_specification.ebs_optimized }}</ebsOptimized>
         <PlacementRequestType>
-          <availabilityZone>{{ request.placement }}</availabilityZone>
+          <availabilityZone>{{ request.launch_specification.placement }}</availabilityZone>
           <groupName></groupName>
         </PlacementRequestType>
       </launchSpecification>
@@ -151,36 +151,36 @@ DESCRIBE_SPOT_INSTANCES_TEMPLATE = """<DescribeSpotInstanceRequestsResponse xmln
         <availabilityZoneGroup>{{ request.availability_zone_group }}</availabilityZoneGroup>
       {% endif %}
       <launchSpecification>
-        <imageId>{{ request.image_id }}</imageId>
-        {% if request.key_name %}
-          <keyName>{{ request.key_name }}</keyName>
+        <imageId>{{ request.launch_specification.image_id }}</imageId>
+        {% if request.launch_specification.key_name %}
+          <keyName>{{ request.launch_specification.key_name }}</keyName>
         {% endif %}
         <groupSet>
-          {% for group in request.security_groups %}
+          {% for group in request.launch_specification.groups %}
           <item>
             <groupId>{{ group.id }}</groupId>
             <groupName>{{ group.name }}</groupName>
           </item>
           {% endfor %}
         </groupSet>
-        {% if request.kernel_id %}
-        <kernelId>{{ request.kernel_id }}</kernelId>
+        {% if request.launch_specification.kernel %}
+        <kernelId>{{ request.launch_specification.kernel }}</kernelId>
         {% endif %}
-        {% if request.ramdisk_id %}
-        <ramdiskId>{{ request.ramdisk_id }}</ramdiskId>
+        {% if request.launch_specification.ramdisk %}
+        <ramdiskId>{{ request.launch_specification.ramdisk }}</ramdiskId>
         {% endif %}
-        {% if request.subnet_id %}
-        <subnetId>{{ request.subnet_id }}</subnetId>
+        {% if request.launch_specification.subnet_id %}
+        <subnetId>{{ request.launch_specification.subnet_id }}</subnetId>
         {% endif %}
-        <instanceType>{{ request.instance_type }}</instanceType>
+        <instanceType>{{ request.launch_specification.instance_type }}</instanceType>
         <blockDeviceMapping/>
         <monitoring>
-          <enabled>{{ request.monitoring_enabled }}</enabled>
+          <enabled>{{ request.launch_specification.monitored }}</enabled>
         </monitoring>
-        <ebsOptimized>{{ request.ebs_optimized }}</ebsOptimized>
-        {% if request.placement %}
+        <ebsOptimized>{{ request.launch_specification.ebs_optimized }}</ebsOptimized>
+        {% if request.launch_specification.placement %}
           <PlacementRequestType>
-            <availabilityZone>{{ request.placement }}</availabilityZone>
+            <availabilityZone>{{ request.launch_specification.placement }}</availabilityZone>
             <groupName></groupName>
           </PlacementRequestType>
         {% endif %}
diff --git a/tests/test_ec2/test_spot_instances.py b/tests/test_ec2/test_spot_instances.py
index 91a3158eb..46a5d7136 100644
--- a/tests/test_ec2/test_spot_instances.py
+++ b/tests/test_ec2/test_spot_instances.py
@@ -4,6 +4,7 @@ import boto
 import sure  # noqa
 
 from moto import mock_ec2
+from moto.backends import get_model
 from moto.core.utils import iso_8601_datetime
 
 
@@ -97,3 +98,29 @@ def test_cancel_spot_instance_request():
 
     requests = conn.get_all_spot_instance_requests()
     requests.should.have.length_of(0)
+
+
+@mock_ec2
+def test_request_spot_instances_fulfilled():
+    """
+    Test that moto correctly fullfills a spot instance request
+    """
+    conn = boto.connect_ec2()
+
+    request = conn.request_spot_instances(
+        price=0.5, image_id='ami-abcd1234',
+    )
+
+    requests = conn.get_all_spot_instance_requests()
+    requests.should.have.length_of(1)
+    request = requests[0]
+
+    request.state.should.equal("open")
+
+    get_model('SpotInstanceRequest')[0].state = 'active'
+
+    requests = conn.get_all_spot_instance_requests()
+    requests.should.have.length_of(1)
+    request = requests[0]
+
+    request.state.should.equal("active")