diff --git a/scapy/fields.py b/scapy/fields.py
index 2e938eb774036b477c0c4bb3436bcb5ce50fdf87..3c4466069d363648d4a24eb187918a88372601bf 100644
--- a/scapy/fields.py
+++ b/scapy/fields.py
@@ -203,7 +203,7 @@ class IPField(Field):
     def __init__(self, name, default):
         Field.__init__(self, name, default, "4s")
     def h2i(self, pkt, x):
-        if type(x) is str:
+        if isinstance(x, basestring):
             try:
                 inet_aton(x)
             except socket.error: