diff --git a/MailCore/Models/Message.swift b/MailCore/Models/Message.swift
index 3290b9807..fee6a561c 100644
--- a/MailCore/Models/Message.swift
+++ b/MailCore/Models/Message.swift
@@ -21,7 +21,7 @@ import MailResources
 import RealmSwift
 
 public class MessageUidsResult: Decodable {
-    public let messageShortUids: [Int]
+    public let messageShortUids: [String]
     public let cursor: String
 
     private enum CodingKeys: String, CodingKey {
@@ -35,7 +35,7 @@ public class MessageByUidsResult: Decodable {
 }
 
 public class MessageDeltaResult: Decodable {
-    public let deletedShortUids: [Int]
+    public let deletedShortUids: [String]
     public let addedShortUids: [String]
     public let updated: [MessageFlags]
     public let cursor: String
@@ -46,6 +46,24 @@ public class MessageDeltaResult: Decodable {
         case updated
         case cursor = "signature"
     }
+
+    // FIXME: Remove this constructor when mixed Int/String arrayis fixed by backend
+    public required init(from decoder: Decoder) throws {
+        let container: KeyedDecodingContainer<CodingKeys> = try decoder.container(keyedBy: CodingKeys.self)
+
+        if let deletedShortUids = try? container.decode([String].self, forKey: .deletedShortUids) {
+            self.deletedShortUids = deletedShortUids
+        } else {
+            deletedShortUids = try container.decode([Int].self, forKey: .deletedShortUids).map { "\($0)" }
+        }
+        if let addedShortUids = try? container.decode([String].self, forKey: .addedShortUids) {
+            self.addedShortUids = addedShortUids
+        } else {
+            addedShortUids = try container.decode([Int].self, forKey: .addedShortUids).map { "\($0)" }
+        }
+        updated = try container.decode([MessageFlags].self, forKey: .updated)
+        cursor = try container.decode(String.self, forKey: .cursor)
+    }
 }
 
 public class MessageFlags: Decodable {