diff --git a/synapse/api/constants.py b/synapse/api/constants.py
index 8cf4d6169cf2f0b4ef000feb23b4cf07da3dea15..a8123cddcbfe338ba7f7fcae0fbe50330a3d438f 100644
--- a/synapse/api/constants.py
+++ b/synapse/api/constants.py
@@ -85,3 +85,8 @@ class RoomCreationPreset(object):
     PRIVATE_CHAT = "private_chat"
     PUBLIC_CHAT = "public_chat"
     TRUSTED_PRIVATE_CHAT = "trusted_private_chat"
+
+
+class ThirdPartyEntityKind(object):
+    USER = "user"
+    LOCATION = "location"
diff --git a/synapse/api/urls.py b/synapse/api/urls.py
index 0fd9b7f244c29172c4d8d7042a921169fb1a26f4..91a33a34020b10243a26500cfdad1fd19aeb353f 100644
--- a/synapse/api/urls.py
+++ b/synapse/api/urls.py
@@ -25,4 +25,3 @@ SERVER_KEY_PREFIX = "/_matrix/key/v1"
 SERVER_KEY_V2_PREFIX = "/_matrix/key/v2"
 MEDIA_PREFIX = "/_matrix/media/r0"
 LEGACY_MEDIA_PREFIX = "/_matrix/media/v1"
-APP_SERVICE_PREFIX = "/_matrix/appservice/v1"
diff --git a/synapse/appservice/api.py b/synapse/appservice/api.py
index d28a9dff0a58f9c0b9547845da067f0cb32a1b46..775417eb212b3b000cbcf253fc66e77163e0f860 100644
--- a/synapse/appservice/api.py
+++ b/synapse/appservice/api.py
@@ -14,11 +14,11 @@
 # limitations under the License.
 from twisted.internet import defer
 
+from synapse.api.constants import ThirdPartyEntityKind
 from synapse.api.errors import CodeMessageException
 from synapse.http.client import SimpleHttpClient
 from synapse.events.utils import serialize_event
 from synapse.util.caches.response_cache import ResponseCache
-from synapse.types import ThirdPartyEntityKind
 
 import logging
 import urllib
@@ -29,6 +29,9 @@ logger = logging.getLogger(__name__)
 HOUR_IN_MS = 60 * 60 * 1000
 
 
+APP_SERVICE_PREFIX = "/_matrix/app/unstable"
+
+
 def _is_valid_3pe_result(r, field):
     if not isinstance(r, dict):
         return False
@@ -103,16 +106,20 @@ class ApplicationServiceApi(SimpleHttpClient):
     @defer.inlineCallbacks
     def query_3pe(self, service, kind, protocol, fields):
         if kind == ThirdPartyEntityKind.USER:
-            uri = "%s/thirdparty/user/%s" % (service.url, urllib.quote(protocol))
             required_field = "userid"
         elif kind == ThirdPartyEntityKind.LOCATION:
-            uri = "%s/thirdparty/location/%s" % (service.url, urllib.quote(protocol))
             required_field = "alias"
         else:
             raise ValueError(
                 "Unrecognised 'kind' argument %r to query_3pe()", kind
             )
 
+        uri = "%s%s/thirdparty/%s/%s" % (
+            service.url,
+            APP_SERVICE_PREFIX,
+            kind,
+            urllib.quote(protocol)
+        )
         try:
             response = yield self.get_json(uri, fields)
             if not isinstance(response, list):
@@ -140,7 +147,11 @@ class ApplicationServiceApi(SimpleHttpClient):
     def get_3pe_protocol(self, service, protocol):
         @defer.inlineCallbacks
         def _get():
-            uri = "%s/thirdparty/protocol/%s" % (service.url, urllib.quote(protocol))
+            uri = "%s%s/thirdparty/protocol/%s" % (
+                service.url,
+                APP_SERVICE_PREFIX,
+                urllib.quote(protocol)
+            )
             try:
                 defer.returnValue((yield self.get_json(uri, {})))
             except Exception as ex:
diff --git a/synapse/rest/client/v2_alpha/thirdparty.py b/synapse/rest/client/v2_alpha/thirdparty.py
index bbc3e9b962f7f37d90de709757426e8191da3c58..4f6f1a7e17dc54a41b1deffce9d78ca27fc36f16 100644
--- a/synapse/rest/client/v2_alpha/thirdparty.py
+++ b/synapse/rest/client/v2_alpha/thirdparty.py
@@ -18,8 +18,8 @@ import logging
 
 from twisted.internet import defer
 
+from synapse.api.constants import ThirdPartyEntityKind
 from synapse.http.servlet import RestServlet
-from synapse.types import ThirdPartyEntityKind
 from ._base import client_v2_patterns
 
 logger = logging.getLogger(__name__)
diff --git a/synapse/types.py b/synapse/types.py
index fd17ecbbe00654cecb6f2374d1f5132172fd5315..5349b0c45000e675e6febcd78867c1f5881afc47 100644
--- a/synapse/types.py
+++ b/synapse/types.py
@@ -269,10 +269,3 @@ class RoomStreamToken(namedtuple("_StreamToken", "topological stream")):
             return "t%d-%d" % (self.topological, self.stream)
         else:
             return "s%d" % (self.stream,)
-
-
-# Some arbitrary constants used for internal API enumerations. Don't rely on
-# exact values; always pass or compare symbolically
-class ThirdPartyEntityKind(object):
-    USER = 'user'
-    LOCATION = 'location'