diff --git a/tools/pin-b64.py b/tools/pin-b64.py
index 3b935dd..59737d7 100644
--- a/tools/pin-b64.py
+++ b/tools/pin-b64.py
@@ -25,7 +25,7 @@
 """
 
 from M2Crypto import X509
-import sys, binascii, hashlib
+import sys, binascii, hashlib, base64
 
 def main(argv):
     if len(argv) < 1: