diff --git a/README.md b/README.md
index 87b48e1..10f0d62 100644
--- a/README.md
+++ b/README.md
@@ -15,6 +15,8 @@ Either download the source from GitHub or use pip:
 ## Sample usage
 
 ```python
+import collections
+
 from apns2.client import APNsClient
 from apns2.payload import Payload