diff --git a/ryu/ofproto/ofproto_v1_3.py b/ryu/ofproto/ofproto_v1_3.py
index 16c47976..4a6dcfef 100644
--- a/ryu/ofproto/ofproto_v1_3.py
+++ b/ryu/ofproto/ofproto_v1_3.py
@@ -1179,6 +1179,12 @@ oxm_types = [
     oxm_fields.ONFExperimenter('pbb_uca', 2560, oxm_fields.Int1),
     oxm_fields.NiciraExtended1('tun_ipv4_src', 31, oxm_fields.IPv4Addr),
     oxm_fields.NiciraExtended1('tun_ipv4_dst', 32, oxm_fields.IPv4Addr),
+
+    # The following definition is merely for testing 64-bit experimenter OXMs.
+    # Following Open vSwitch, we use dp_hash for this purpose.
+    # Prefix the name with '_' to indicate this is not intended to be used
+    # in wild.
+    oxm_fields.NiciraExperimenter('_dp_hash', 0, oxm_fields.Int4),
 ]
 
 oxm_fields.generate(__name__)
diff --git a/ryu/ofproto/oxm_fields.py b/ryu/ofproto/oxm_fields.py
index ab33cddb..0004f86b 100644
--- a/ryu/ofproto/oxm_fields.py
+++ b/ryu/ofproto/oxm_fields.py
@@ -150,6 +150,10 @@ class ONFExperimenter(_Experimenter):
         self.exp_type = num
 
 
+class NiciraExperimenter(_Experimenter):
+    experimenter_id = ofproto_common.NX_EXPERIMENTER_ID
+
+
 class NiciraExtended0(_OxmClass):
     """Nicira Extended Match (NXM_0)
 
diff --git a/ryu/tests/unit/ofproto/test_oxm.py b/ryu/tests/unit/ofproto/test_oxm.py
index b3336675..a2047f8b 100644
--- a/ryu/tests/unit/ofproto/test_oxm.py
+++ b/ryu/tests/unit/ofproto/test_oxm.py
@@ -75,6 +75,25 @@ class Test_OXM(unittest.TestCase):
         )
         self._test(user, on_wire, 4)
 
+    def test_exp_nomask(self):
+        user = ('_dp_hash', 0x12345678)
+        on_wire = (
+            b'\xff\xff\x00\x08'
+            b'\x00\x00\x23\x20'  # Nicira
+            b'\x12\x34\x56\x78'
+        )
+        self._test(user, on_wire, 8)
+
+    def test_exp_mask(self):
+        user = ('_dp_hash', (0x12345678, 0x7fffffff))
+        on_wire = (
+            b'\xff\xff\x01\x0c'
+            b'\x00\x00\x23\x20'  # Nicira
+            b'\x12\x34\x56\x78'
+            b'\x7f\xff\xff\xff'
+        )
+        self._test(user, on_wire, 8)
+
     def test_nxm_1_nomask(self):
         user = ('tun_ipv4_src', '192.0.2.1')
         on_wire = (