diff --git a/synapse/rest/client/v2_alpha/filter.py b/synapse/rest/client/v2_alpha/filter.py
index 510f8b2c74..f7758fc68c 100644
--- a/synapse/rest/client/v2_alpha/filter.py
+++ b/synapse/rest/client/v2_alpha/filter.py
@@ -15,7 +15,7 @@
 
 from twisted.internet import defer
 
-from synapse.api.errors import AuthError, SynapseError
+from synapse.api.errors import AuthError, SynapseError, StoreError, Codes
 from synapse.http.servlet import RestServlet, parse_json_object_from_request
 from synapse.types import UserID
 
@@ -45,7 +45,7 @@ class GetFilterRestServlet(RestServlet):
             raise AuthError(403, "Cannot get filters for other users")
 
         if not self.hs.is_mine(target_user):
-            raise SynapseError(400, "Can only get filters for local users")
+            raise AuthError(403, "Can only get filters for local users")
 
         try:
             filter_id = int(filter_id)
@@ -59,8 +59,8 @@ class GetFilterRestServlet(RestServlet):
             )
 
             defer.returnValue((200, filter.get_filter_json()))
-        except KeyError:
-            raise SynapseError(400, "No such filter")
+        except (KeyError, StoreError):
+            raise SynapseError(400, "No such filter", errcode=Codes.NOT_FOUND)
 
 
 class CreateFilterRestServlet(RestServlet):
diff --git a/tests/rest/client/v2_alpha/test_filter.py b/tests/rest/client/v2_alpha/test_filter.py
index d1442aafac..47ca5e8c8a 100644
--- a/tests/rest/client/v2_alpha/test_filter.py
+++ b/tests/rest/client/v2_alpha/test_filter.py
@@ -19,7 +19,7 @@ from . import V2AlphaRestTestCase
 
 from synapse.rest.client.v2_alpha import filter
 
-from synapse.api.errors import StoreError
+from synapse.api.errors import StoreError, Codes
 
 
 class FilterTestCase(V2AlphaRestTestCase):
@@ -82,11 +82,20 @@ class FilterTestCase(V2AlphaRestTestCase):
         (code, response) = yield self.mock_resource.trigger_get(
             "/user/%s/filter/2" % (self.USER_ID)
         )
-        self.assertEquals(404, code)
+        self.assertEquals(400, code)
 
     @defer.inlineCallbacks
     def test_get_filter_no_user(self):
         (code, response) = yield self.mock_resource.trigger_get(
             "/user/%s/filter/0" % (self.USER_ID)
         )
-        self.assertEquals(404, code)
+        self.assertEquals(400, code)
+        self.assertEquals(response['errcode'], Codes.FORBIDDEN)
+
+    @defer.inlineCallbacks
+    def test_get_filter_missing_id(self):
+        (code, response) = yield self.mock_resource.trigger_get(
+            "/user/%s/filter/0" % (self.USER_ID)
+        )
+        self.assertEquals(400, code)
+        self.assertEquals(response['errcode'], Codes.NOT_FOUND)