diff --git a/src/ACMESharp/Protocol/AcmeProtocolClient.cs b/src/ACMESharp/Protocol/AcmeProtocolClient.cs
index 7169bd4..0913271 100644
--- a/src/ACMESharp/Protocol/AcmeProtocolClient.cs
+++ b/src/ACMESharp/Protocol/AcmeProtocolClient.cs
@@ -380,6 +380,7 @@ public async Task<AccountDetails> DeactivateAccountAsync(
         /// https://tools.ietf.org/html/draft-ietf-acme-acme-12#section-7.1.3
         /// </remarks>
         public async Task<OrderDetails> CreateOrderAsync(IEnumerable<Identifier> identifiers,
+            string replacesCertificateId = null,
             DateTime? notBefore = null,
             DateTime? notAfter = null,
             CancellationToken cancel = default(CancellationToken))
@@ -389,6 +390,7 @@ public async Task<OrderDetails> CreateOrderAsync(IEnumerable<Identifier> identif
                 Identifiers = identifiers.ToArray(),
                 NotBefore = notBefore?.ToString(Constants.Rfc3339DateTimeFormat),
                 NotAfter = notAfter?.ToString(Constants.Rfc3339DateTimeFormat),
+                Replaces = replacesCertificateId	
             };
             var resp = await SendAcmeAsync(
                     new Uri(_http.BaseAddress, Directory.NewOrder),
@@ -412,11 +414,12 @@ public async Task<OrderDetails> CreateOrderAsync(IEnumerable<Identifier> identif
         /// https://tools.ietf.org/html/draft-ietf-acme-acme-12#section-7.1.3
         /// </remarks>
         public Task<OrderDetails> CreateOrderAsync(IEnumerable<string> dnsIdentifiers,
+            string replacesCertificateId = null,
             DateTime? notBefore = null,
             DateTime? notAfter = null,
             CancellationToken cancel = default(CancellationToken)) => CreateOrderAsync(
                 dnsIdentifiers.Select(dns => new Identifier() { Type = "dns", Value = dns }).ToArray(),
-                notBefore, notAfter, cancel);
+                replacesCertificateId, notBefore, notAfter,  cancel);
 
         /// <summary>
         /// Retrieves the current status and details of an existing Order.
diff --git a/src/ACMESharp/Protocol/Messages/CreateOrderRequest.cs b/src/ACMESharp/Protocol/Messages/CreateOrderRequest.cs
index bd1a8a7..ae14581 100644
--- a/src/ACMESharp/Protocol/Messages/CreateOrderRequest.cs
+++ b/src/ACMESharp/Protocol/Messages/CreateOrderRequest.cs
@@ -19,5 +19,8 @@ public class CreateOrderRequest
 
         [JsonProperty("notAfter", NullValueHandling = NullValueHandling.Ignore)]
         public string NotAfter { get; set; }
+
+        [JsonProperty("replaces", NullValueHandling = NullValueHandling.Ignore)]
+        public string Replaces { get; set; }
     }
 }
\ No newline at end of file
diff --git a/src/ACMESharp/Protocol/Resources/ServiceDirectory.cs b/src/ACMESharp/Protocol/Resources/ServiceDirectory.cs
index 6ff74a5..d9c82dc 100644
--- a/src/ACMESharp/Protocol/Resources/ServiceDirectory.cs
+++ b/src/ACMESharp/Protocol/Resources/ServiceDirectory.cs
@@ -34,6 +34,9 @@ public class ServiceDirectory
         [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
         public string KeyChange { get; set; } //! = "acme/key-change";
 
+        [JsonProperty(NullValueHandling = NullValueHandling.Ignore)]
+        public string RenewalInfo { get; set; } //! = "acme/renewal-info";
+
         public DirectoryMeta Meta { get; set; }
 
         public IEnumerable<string> GetExtraNames() => _extra?.Keys;