diff --git a/openstackclient/network/v2/security_group_rule.py b/openstackclient/network/v2/security_group_rule.py
index ca0e00b9d8..961125a9a7 100644
--- a/openstackclient/network/v2/security_group_rule.py
+++ b/openstackclient/network/v2/security_group_rule.py
@@ -73,6 +73,14 @@ def _convert_to_lowercase(string):
     return string.lower()
 
 
+def _convert_ipvx_case(string):
+    if string.lower() == 'ipv4':
+        return 'IPv4'
+    if string.lower() == 'ipv6':
+        return 'IPv6'
+    return string
+
+
 def _is_icmp_protocol(protocol):
     # NOTE(rtheis): Neutron has deprecated protocol icmpv6.
     # However, while the OSC CLI doesn't document the protocol,
@@ -183,6 +191,7 @@ class CreateSecurityGroupRule(common.NetworkAndComputeShowOne):
             '--ethertype',
             metavar='<ethertype>',
             choices=['IPv4', 'IPv6'],
+            type=_convert_ipvx_case,
             help=_("Ethertype of network traffic "
                    "(IPv4, IPv6; default: based on IP protocol)")
         )
diff --git a/openstackclient/tests/unit/network/v2/test_security_group_rule_network.py b/openstackclient/tests/unit/network/v2/test_security_group_rule_network.py
index fe6d364928..b070ab6aab 100644
--- a/openstackclient/tests/unit/network/v2/test_security_group_rule_network.py
+++ b/openstackclient/tests/unit/network/v2/test_security_group_rule_network.py
@@ -125,6 +125,30 @@ class TestCreateSecurityGroupRuleNetwork(TestSecurityGroupRuleNetwork):
         self.assertRaises(tests_utils.ParserException,
                           self.check_parser, self.cmd, arglist, [])
 
+    def test_lowercase_ethertype(self):
+        arglist = [
+            '--ethertype', 'ipv4',
+            self._security_group.id,
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, [])
+        self.assertEqual('IPv4', parsed_args.ethertype)
+
+    def test_lowercase_v6_ethertype(self):
+        arglist = [
+            '--ethertype', 'ipv6',
+            self._security_group.id,
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, [])
+        self.assertEqual('IPv6', parsed_args.ethertype)
+
+    def test_proper_case_ethertype(self):
+        arglist = [
+            '--ethertype', 'IPv6',
+            self._security_group.id,
+        ]
+        parsed_args = self.check_parser(self.cmd, arglist, [])
+        self.assertEqual('IPv6', parsed_args.ethertype)
+
     def test_create_all_protocol_options(self):
         arglist = [
             '--protocol', 'tcp',