diff --git a/specification/network/resource-manager/Microsoft.Network/stable/2019-02-01/networkSecurityGroup.json b/specification/network/resource-manager/Microsoft.Network/stable/2019-02-01/networkSecurityGroup.json
index 9b9a6abfc1c7..7a1ecf6eadbb 100644
--- a/specification/network/resource-manager/Microsoft.Network/stable/2019-02-01/networkSecurityGroup.json
+++ b/specification/network/resource-manager/Microsoft.Network/stable/2019-02-01/networkSecurityGroup.json
@@ -615,10 +615,13 @@
         },
         "protocol": {
           "type": "string",
-          "description": "Network protocol this rule applies to. Possible values are 'Tcp', 'Udp', and '*'.",
+          "description": "Network protocol this rule applies to. Possible values are 'Tcp', 'Udp', 'Icmp', 'Esp', 'Ah', and '*'.",
           "enum": [
             "Tcp",
             "Udp",
+            "Icmp",
+            "Esp",
+            "Ah",
             "*"
           ],
           "x-ms-enum": {