diff --git a/src/GregsStack.PushCrew.Net.Api/IPushCrewClient.cs b/src/GregsStack.PushCrew.Net.Api/IPushCrewClient.cs
index e1bb5c9..a0bc260 100644
--- a/src/GregsStack.PushCrew.Net.Api/IPushCrewClient.cs
+++ b/src/GregsStack.PushCrew.Net.Api/IPushCrewClient.cs
@@ -15,11 +15,11 @@ public interface IPushCrewClient
         Task<SendMessageResponse> SendSubscriberAsync(SendMessageRequest request, string subscriberId);
         Task<NotificationStatusResponse> CheckNotificationRequestStatusAsync(string id);
         Task<ScheduleMessageResponse> ScheduleAllSubscribersAsync(ScheduleMessageRequest request);
-        Task<ScheduleMessageResponse> ScheduleSegmentAsync(ScheduleMessageRequest request, string segmentId);
+        Task<ScheduleMessageResponse> ScheduleSegmentAsync(ScheduleMessageRequest request, long segmentId);
         Task<SegmentResponse> AddSegmentAsync(string name);
         Task<SegmentsResponse> ListSegmentsAsync();
-        Task<SegmentResponse> AddSubscribersToSegmentAsync(string segmentId, ICollection<string> subscriberList);
-        Task<SubscribersResponse> ListSubscribersInSegmentAsync(string segmentId, int page = 1, int perPage = 1024);
+        Task<SegmentResponse> AddSubscribersToSegmentAsync(long segmentId, ICollection<string> subscriberList);
+        Task<SubscribersResponse> ListSubscribersInSegmentAsync(long segmentId, int page = 1, int perPage = 1024);
         Task<SubscribersResponse> ListSegmentsOfSubscriberAsync(string subscriberId);
         Task<StatusResponse> RemoveSubscribersAsync(long segmentId, RemoveSubscriberRequest removeSubscriberRequest);
         Task<StatusResponse> DeleteSegmentAsync(long segmentId);
diff --git a/src/GregsStack.PushCrew.Net.Api/PushCrewClient.cs b/src/GregsStack.PushCrew.Net.Api/PushCrewClient.cs
index 36d2bcf..de79d8c 100644
--- a/src/GregsStack.PushCrew.Net.Api/PushCrewClient.cs
+++ b/src/GregsStack.PushCrew.Net.Api/PushCrewClient.cs
@@ -90,7 +90,7 @@ public async Task<ScheduleMessageResponse> ScheduleAllSubscribersAsync(ScheduleM
             return await this.PostAsync<ScheduleMessageRequest, ScheduleMessageResponse>(request, relativeUri);
         }
 
-        public async Task<ScheduleMessageResponse> ScheduleSegmentAsync(ScheduleMessageRequest request, string segmentId)
+        public async Task<ScheduleMessageResponse> ScheduleSegmentAsync(ScheduleMessageRequest request, long segmentId)
         {
             var relativeUri = $"send/segment/{segmentId}";
             return await this.PostAsync<ScheduleMessageRequest, ScheduleMessageResponse>(request, relativeUri);
@@ -109,7 +109,7 @@ public async Task<SegmentsResponse> ListSegmentsAsync()
             return await this.GetAsync<SegmentsResponse>(relativeUri);
         }
 
-        public async Task<SegmentResponse> AddSubscribersToSegmentAsync(string segmentId, ICollection<string> subscriberList)
+        public async Task<SegmentResponse> AddSubscribersToSegmentAsync(long segmentId, ICollection<string> subscriberList)
         {
             var relativeUri = $"segments/{segmentId}/subscribers";
 
@@ -123,7 +123,7 @@ public async Task<SegmentResponse> AddSubscribersToSegmentAsync(string segmentId
             return await this.PostAsync<SendMessageSubscribersRequest, SegmentResponse>(subscriberRequest, relativeUri);
         }
 
-        public async Task<SubscribersResponse> ListSubscribersInSegmentAsync(string segmentId, int page = 1, int perPage = 1024)
+        public async Task<SubscribersResponse> ListSubscribersInSegmentAsync(long segmentId, int page = 1, int perPage = 1024)
         {
             var relativeUri = $"segments/{segmentId}/subscribers?page={page}&per_page={perPage}";
             return await this.GetAsync<SubscribersResponse>(relativeUri);
diff --git a/src/GregsStack.PushCrew.Net.Api/Response/Models/Segment.cs b/src/GregsStack.PushCrew.Net.Api/Response/Models/Segment.cs
index ba47b63..5f63032 100644
--- a/src/GregsStack.PushCrew.Net.Api/Response/Models/Segment.cs
+++ b/src/GregsStack.PushCrew.Net.Api/Response/Models/Segment.cs
@@ -4,11 +4,11 @@ namespace GregsStack.PushCrew.Net.Api.Response.Models
 
     public class Segment
     {
-        public string Id { get; set; }
+        public long Id { get; set; }
 
         public string Name { get; set; }
 
-        public Segment(string id, string name)
+        public Segment(long id, string name)
         {
             this.Id = id;
             this.Name = name ?? throw new ArgumentNullException(nameof(name));
diff --git a/src/GregsStack.PushCrew.Net.Api/Response/SegmentResponse.cs b/src/GregsStack.PushCrew.Net.Api/Response/SegmentResponse.cs
index b7dd1ca..2889356 100644
--- a/src/GregsStack.PushCrew.Net.Api/Response/SegmentResponse.cs
+++ b/src/GregsStack.PushCrew.Net.Api/Response/SegmentResponse.cs
@@ -6,7 +6,7 @@ public class SegmentResponse : StatusResponse
         /// To identify the segment newly created.
         /// The same ID is used to add/remove subscribers to/from the segment through the API.
         /// </summary>
-        public string SegmentId { get; set; }
+        public long SegmentId { get; set; }
 
         /// <summary>
         /// Present in case of failure. Used to denote reason of failure.