diff --git a/hgext/infinitepush/fileindexapi.py b/hgext/infinitepush/fileindexapi.py
--- a/hgext/infinitepush/fileindexapi.py
+++ b/hgext/infinitepush/fileindexapi.py
@@ -15,11 +15,16 @@
 
 import os
 
+from mercurial.thirdparty.zope import (
+    interface as zi,
+)
+
 from mercurial.utils import stringutil
 
 from . import indexapi
 
-class fileindexapi(indexapi.indexapi):
+@zi.implementer(indexapi.indexapi)
+class fileindexapi(object):
     def __init__(self, repo):
         super(fileindexapi, self).__init__()
         self._repo = repo
diff --git a/hgext/infinitepush/indexapi.py b/hgext/infinitepush/indexapi.py
--- a/hgext/infinitepush/indexapi.py
+++ b/hgext/infinitepush/indexapi.py
@@ -7,7 +7,11 @@
 
 from __future__ import absolute_import
 
-class indexapi(object):
+from mercurial.thirdparty.zope import (
+    interface as zi,
+)
+
+class indexapi(zi.Interface):
     """Class that manages access to infinitepush index.
 
     This class is a context manager and all write operations (like
diff --git a/hgext/infinitepush/sqlindexapi.py b/hgext/infinitepush/sqlindexapi.py
--- a/hgext/infinitepush/sqlindexapi.py
+++ b/hgext/infinitepush/sqlindexapi.py
@@ -14,6 +14,10 @@
 import warnings
 import mysql.connector
 
+from mercurial.thirdparty.zope import (
+    interface as zi,
+)
+
 from . import indexapi
 
 def _convertbookmarkpattern(pattern):
@@ -23,7 +27,8 @@
         pattern = pattern[:-1] + '%'
     return pattern
 
-class sqlindexapi(indexapi.indexapi):
+@zi.implementer(indexapi.indexapi)
+class sqlindexapi(object):
     '''
     Sql backend for infinitepush index. See schema.sql
     '''