diff --git a/src/InternshipSystem.Api/Controllers/InternshipController.cs b/src/InternshipSystem.Api/Controllers/InternshipController.cs
index e52bc44..9fdfa47 100644
--- a/src/InternshipSystem.Api/Controllers/InternshipController.cs
+++ b/src/InternshipSystem.Api/Controllers/InternshipController.cs
@@ -44,6 +44,7 @@ namespace InternshipSystem.Api.Controllers
                 .Include(i => i.InternshipRegistration.Company)
                 .Include(i => i.InternshipRegistration.BranchAddress)
                 .Include(i => i.InternshipRegistration.Type)
+                .Include(i => i.InternshipRegistration.Subjects)
                 .Include(i => i.Report)
                 .Include(i => i.Documentation)
                 .SingleAsync(i => i.Student.Id == user.PersonNumber, cancellationToken);
diff --git a/src/InternshipSystem.Api/Converters/StringArrayConverter.cs b/src/InternshipSystem.Api/Converters/StringArrayConverter.cs
new file mode 100644
index 0000000..e4c80ce
--- /dev/null
+++ b/src/InternshipSystem.Api/Converters/StringArrayConverter.cs
@@ -0,0 +1,37 @@
+using System;
+using System.Collections.Generic;
+using Newtonsoft.Json;
+using Newtonsoft.Json.Linq;
+
+namespace InternshipSystem.Api.Converters
+{
+    public class StringArrayConverter<TItem> : JsonConverter
+    {
+        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
+        {
+            throw new NotImplementedException();
+        }
+
+        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
+        {
+            var token = JToken.Load(reader);
+
+            if (token.Type == JTokenType.Array)
+            {
+                return token.ToObject<List<TItem>>();
+            }
+            
+            return new List<TItem>
+            {
+                token.ToObject<TItem>()
+            };
+        }
+
+        public override bool CanConvert(Type objectType)
+        {
+            return objectType == typeof(List<TItem>);
+        }
+
+        public override bool CanWrite => false;
+    }
+}
\ No newline at end of file
diff --git a/src/InternshipSystem.Api/GutCasClient.cs b/src/InternshipSystem.Api/GutCasClient.cs
index 08f0714..75784b6 100644
--- a/src/InternshipSystem.Api/GutCasClient.cs
+++ b/src/InternshipSystem.Api/GutCasClient.cs
@@ -1,11 +1,13 @@
 using System.Collections.Generic;
+using System.IO;
 using System.Net.Http;
 using System.Net.Http.Headers;
-using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
 using InternshipSystem.Api.Options;
 using Microsoft.Extensions.Options;
+using Newtonsoft.Json;
+using JsonConverter = System.Text.Json.Serialization.JsonConverter;
 
 namespace InternshipSystem.Api.Controllers
 {
@@ -39,9 +41,9 @@ namespace InternshipSystem.Api.Controllers
             };
 
             var response = await _client.SendAsync(request, cancellationToken);
-            await using var stream = await response.Content.ReadAsStreamAsync();
+            var content = await response.Content.ReadAsStringAsync();
 
-            var value = await JsonSerializer.DeserializeAsync<Dictionary<string, object>>(stream);
+            var value = JsonConvert.DeserializeObject<Dictionary<string, object>>(content);
 
             return value["access_token"].ToString();
         }
@@ -60,15 +62,10 @@ namespace InternshipSystem.Api.Controllers
             request.Content.Headers.ContentType = MediaTypeHeaderValue.Parse("application/json");
 
             var response = await _client.SendAsync(request, cancellationToken);
-            await using var stream = await response.Content.ReadAsStreamAsync();
-            
-            var result = await JsonSerializer.DeserializeAsync<CasUserProfile>(
-                stream, 
-                new JsonSerializerOptions
-                {
-                    PropertyNameCaseInsensitive = true
-                });
+            var content = await response.Content.ReadAsStringAsync();
 
+            var result = JsonConvert.DeserializeObject<CasUserProfile>(content);
+                
             return result.Attributes;
         }
     }
diff --git a/src/InternshipSystem.Api/InternshipSystem.Api.csproj b/src/InternshipSystem.Api/InternshipSystem.Api.csproj
index f512388..123f3c3 100644
--- a/src/InternshipSystem.Api/InternshipSystem.Api.csproj
+++ b/src/InternshipSystem.Api/InternshipSystem.Api.csproj
@@ -18,7 +18,7 @@
     <PackageReference Include="Serilog.AspNetCore" Version="3.2.0" />
     <PackageReference Include="Serilog.Sinks.Console" Version="3.1.1" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="5.6.3" />
-    <PackageReference Include="Swashbuckle.AspNetCore.Newtonsoft" Version="5.6.3"/>
+    <PackageReference Include="Swashbuckle.AspNetCore.Newtonsoft" Version="5.6.3" />
     <PackageReference Include="IdentityServer4" Version="3.1.4" />
   </ItemGroup>
 
diff --git a/src/InternshipSystem.Api/Result/CasUserData.cs b/src/InternshipSystem.Api/Result/CasUserData.cs
index 560a3ac..14c90dd 100644
--- a/src/InternshipSystem.Api/Result/CasUserData.cs
+++ b/src/InternshipSystem.Api/Result/CasUserData.cs
@@ -1,4 +1,6 @@
 using System.Collections.Generic;
+using InternshipSystem.Api.Converters;
+using Newtonsoft.Json;
 
 namespace InternshipSystem.Api.Controllers
 {
@@ -7,8 +9,12 @@ namespace InternshipSystem.Api.Controllers
         public string AlbumNumber { get; set; }
         public string FirstName { get; set; }
         public string LastName { get; set; }
+        
+        [JsonConverter(typeof(StringArrayConverter<string>))]
         public List<string> Mail { get; set; }
         public string PersonNumber { get; set; }
+        
+        [JsonConverter(typeof(StringArrayConverter<string>))]
         public List<string> Pg_Cui_Portalroles { get; set; }
     }
 }
\ No newline at end of file