diff --git a/src/Core/Services/BitwardenFileUploadService.cs b/src/Core/Services/BitwardenFileUploadService.cs
index 88295c0a9..bb0c29073 100644
--- a/src/Core/Services/BitwardenFileUploadService.cs
+++ b/src/Core/Services/BitwardenFileUploadService.cs
@@ -1,5 +1,7 @@
 using System;
 using System.Net.Http;
+using System.Net.Http.Headers;
+using System.Net.Mime;
 using System.Threading.Tasks;
 using Bit.Core.Models.Domain;
 
@@ -18,7 +20,7 @@ namespace Bit.Core.Services
         {
             var fd = new MultipartFormDataContent($"--BWMobileFormBoundary{DateTime.UtcNow.Ticks}")
             {
-                { new ByteArrayContent(encryptedFileData.Buffer), "data", encryptedFileName }
+                { new ByteArrayContent(encryptedFileData.Buffer) { Headers = { ContentType = new MediaTypeHeaderValue(MediaTypeNames.Application.Octet) } }, "data", encryptedFileName }
             };
 
             await apiCall(fd);