diff --git a/Milter/utils.py b/Milter/utils.py
index d8d55164b204bef1877600ab5f2274ef1d58352e..c8c3428e1768d58399b34d9fb16499fa8b11edb8 100644
--- a/Milter/utils.py
+++ b/Milter/utils.py
@@ -49,7 +49,7 @@ if hasattr(socket,'has_ipv6') and socket.has_ipv6:
     def inet_ntop(s):
         return socket.inet_ntop(socket.AF_INET6,s)
     def inet_pton(s):
-        return socket.inet_pton(socket.AF_INET6,s)
+        return socket.inet_pton(socket.AF_INET6,s.strip())
 else:
     from pyip6 import inet_ntop, inet_pton