diff --git a/KeyVault.Acmebot/Internal/AzureSdkExtensions.cs b/KeyVault.Acmebot/Internal/AzureSdkExtensions.cs
new file mode 100644
index 00000000..ac31832d
--- /dev/null
+++ b/KeyVault.Acmebot/Internal/AzureSdkExtensions.cs
@@ -0,0 +1,49 @@
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+using Microsoft.Azure.KeyVault;
+using Microsoft.Azure.KeyVault.Models;
+using Microsoft.Azure.Management.Dns;
+using Microsoft.Azure.Management.Dns.Models;
+
+namespace KeyVault.Acmebot.Internal
+{
+    internal static class AzureSdkExtensions
+    {
+        public static async Task<IList<Zone>> ListAllAsync(this IZonesOperations operations)
+        {
+            var zones = new List<Zone>();
+
+            var list = await operations.ListAsync();
+
+            zones.AddRange(list);
+
+            while (list.NextPageLink != null)
+            {
+                list = await operations.ListNextAsync(list.NextPageLink);
+
+                zones.AddRange(list);
+            }
+
+            return zones;
+        }
+
+        public static async Task<IList<CertificateItem>> GetAllCertificatesAsync(this IKeyVaultClient keyVaultClient, string vaultBaseUrl)
+        {
+            var certificates = new List<CertificateItem>();
+
+            var list = await keyVaultClient.GetCertificatesAsync(vaultBaseUrl);
+
+            certificates.AddRange(list);
+
+            while (list.NextPageLink != null)
+            {
+                list = await keyVaultClient.GetCertificatesNextAsync(list.NextPageLink);
+
+                certificates.AddRange(list);
+            }
+
+            return certificates;
+        }
+    }
+}
diff --git a/KeyVault.Acmebot/SharedFunctions.cs b/KeyVault.Acmebot/SharedFunctions.cs
index 5fd739ed..b9f2d056 100644
--- a/KeyVault.Acmebot/SharedFunctions.cs
+++ b/KeyVault.Acmebot/SharedFunctions.cs
@@ -80,7 +80,7 @@ public async Task IssueCertificate([OrchestrationTrigger] DurableOrchestrationCo
         [FunctionName(nameof(GetCertificates))]
         public async Task<IList<CertificateBundle>> GetCertificates([ActivityTrigger] DateTime currentDateTime)
         {
-            var certificates = await _keyVaultClient.GetCertificatesAsync(Settings.Default.VaultBaseUrl);
+            var certificates = await _keyVaultClient.GetAllCertificatesAsync(Settings.Default.VaultBaseUrl);
 
             var list = certificates.Where(x => x.Tags != null && x.Tags.TryGetValue("Issuer", out var issuer) && issuer == "letsencrypt.org")
                                    .Where(x => (x.Attributes.Expires.Value - currentDateTime).TotalDays < 30)
@@ -97,22 +97,9 @@ public async Task<IList<CertificateBundle>> GetCertificates([ActivityTrigger] Da
         }
 
         [FunctionName(nameof(GetZones))]
-        public async Task<IList<Zone>> GetZones([ActivityTrigger] object input = null)
+        public Task<IList<Zone>> GetZones([ActivityTrigger] object input = null)
         {
-            var list = await _dnsManagementClient.Zones.ListAsync();
-
-            var zones = new List<Zone>();
-
-            zones.AddRange(list);
-
-            while (list.NextPageLink != null)
-            {
-                list = await _dnsManagementClient.Zones.ListNextAsync(list.NextPageLink);
-
-                zones.AddRange(list);
-            }
-
-            return zones;
+            return _dnsManagementClient.Zones.ListAllAsync();
         }
 
         [FunctionName(nameof(Order))]
@@ -127,7 +114,7 @@ public async Task<OrderDetails> Order([ActivityTrigger] string[] hostNames)
         public async Task Dns01Precondition([ActivityTrigger] string[] hostNames)
         {
             // Azure DNS が存在するか確認
-            var zones = await _dnsManagementClient.Zones.ListAsync();
+            var zones = await _dnsManagementClient.Zones.ListAllAsync();
 
             foreach (var hostName in hostNames)
             {
@@ -153,7 +140,7 @@ public async Task<ChallengeResult> Dns01Authorization([ActivityTrigger] (string,
             var challengeValidationDetails = AuthorizationDecoder.ResolveChallengeForDns01(authz, challenge, acmeProtocolClient.Signer);
 
             // Azure DNS の TXT レコードを書き換え
-            var zone = (await _dnsManagementClient.Zones.ListAsync()).First(x => challengeValidationDetails.DnsRecordName.EndsWith(x.Name));
+            var zone = (await _dnsManagementClient.Zones.ListAllAsync()).First(x => challengeValidationDetails.DnsRecordName.EndsWith(x.Name));
 
             var resourceId = ParseResourceId(zone.Id);