diff --git a/src/sipcentric/__init__.py b/src/sipcentric/__init__.py
index d4fd83f..ca1c289 100644
--- a/src/sipcentric/__init__.py
+++ b/src/sipcentric/__init__.py
@@ -238,7 +238,7 @@ class Customer(APIObject):
             yield PhoneNumber(self._api, data=c)
 
     def calls(self, params=None):
-        for c in self._api.getMany(Call.makeUrl(parent=self, params=params, pageSize=100):
+        for c in self._api.getMany(Call.makeUrl(parent=self, params=params, pageSize=100)):
             yield Call(self._api, data=c)
 
     def callbundles(self):