diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index 22123467cd..0b5e7d4782 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -1131,6 +1131,7 @@ class GenericIPAddressField(Field):
     def __init__(self, verbose_name=None, name=None, protocol='both',
                  unpack_ipv4=False, *args, **kwargs):
         self.unpack_ipv4 = unpack_ipv4
+        self.protocol = protocol
         self.default_validators, invalid_error_message = \
             validators.ip_address_validators(protocol, unpack_ipv4)
         self.default_error_messages['invalid'] = invalid_error_message