diff --git a/api/core.py b/api/core.py
index 128349f..5fd8ff0 100644
--- a/api/core.py
+++ b/api/core.py
@@ -1,6 +1,6 @@
 from flask import Flask, jsonify, Response, request
 from flask_sqlalchemy import SQLAlchemy
-from api.extensions.esales import Esales
+from esales.flask_esales import Esales
 from api.helpers import check_api_key
 from api.exceptions import ValidationError
 
diff --git a/api/extensions/__init__.py b/api/extensions/__init__.py
deleted file mode 100644
index e69de29..0000000
diff --git a/api/extensions/esales.py b/esales/flask_esales.py
similarity index 63%
rename from api/extensions/esales.py
rename to esales/flask_esales.py
index f740a6d..2ea37c1 100644
--- a/api/extensions/esales.py
+++ b/esales/flask_esales.py
@@ -1,4 +1,4 @@
-from esales.cluster import Cluster
+from .cluster import Cluster
 
 
 class Esales(object):
@@ -10,4 +10,6 @@ class Esales(object):
             self.init_app(app)
 
     def init_app(self, app):
+        if not 'ESALES_URL' in app.config:
+            raise Exception('ESALES_URL missing in config')
         self.cluster.url = app.config.get('ESALES_URL')