diff --git a/src/Machine/src/Serval.Machine.Shared/Services/NmtClearMLBuildJobFactory.cs b/src/Machine/src/Serval.Machine.Shared/Services/NmtClearMLBuildJobFactory.cs
index 4ab83dc4..4758a7b5 100644
--- a/src/Machine/src/Serval.Machine.Shared/Services/NmtClearMLBuildJobFactory.cs
+++ b/src/Machine/src/Serval.Machine.Shared/Services/NmtClearMLBuildJobFactory.cs
@@ -41,7 +41,11 @@ public async Task<string> CreateJobScriptAsync(
                 + $"    'trg_lang': '{trgLang}',\n"
                 + $"    'shared_file_uri': '{baseUri}',\n"
                 + $"    'shared_file_folder': '{folder}',\n"
-                + (buildOptions is not null ? $"    'build_options': '''{buildOptions}''',\n" : "")
+                + (
+                    buildOptions is not null
+                        ? $"    'build_options': '''{Convert.ToBase64String(Encoding.UTF8.GetBytes(buildOptions))}''',\n"
+                        : ""
+                )
                 // buildRevision + 1 because the build revision is incremented after the build job
                 // is finished successfully but the file should be saved with the new revision number
                 + (engine.IsModelPersisted ? $"    'save_model': '{engineId}_{engine.BuildRevision + 1}',\n" : $"")
diff --git a/src/Machine/src/Serval.Machine.Shared/Services/SmtTransferClearMLBuildJobFactory.cs b/src/Machine/src/Serval.Machine.Shared/Services/SmtTransferClearMLBuildJobFactory.cs
index 0552c093..ca5ba04b 100644
--- a/src/Machine/src/Serval.Machine.Shared/Services/SmtTransferClearMLBuildJobFactory.cs
+++ b/src/Machine/src/Serval.Machine.Shared/Services/SmtTransferClearMLBuildJobFactory.cs
@@ -35,7 +35,11 @@ public async Task<string> CreateJobScriptAsync(
                 + $"    'build_id': '{buildId}',\n"
                 + $"    'shared_file_uri': '{baseUri}',\n"
                 + $"    'shared_file_folder': '{folder}',\n"
-                + (buildOptions is not null ? $"    'build_options': '''{buildOptions}''',\n" : "")
+                + (
+                    buildOptions is not null
+                        ? $"    'build_options': '''{Convert.ToBase64String(Encoding.UTF8.GetBytes(buildOptions))}''',\n"
+                        : ""
+                )
                 + $"    'clearml': True\n"
                 + "}\n"
                 + "run(args)\n";
diff --git a/src/Machine/src/Serval.Machine.Shared/Services/StatsiticalClearMLBuildJobFactory.cs b/src/Machine/src/Serval.Machine.Shared/Services/StatisticalClearMLBuildJobFactory.cs
similarity index 88%
rename from src/Machine/src/Serval.Machine.Shared/Services/StatsiticalClearMLBuildJobFactory.cs
rename to src/Machine/src/Serval.Machine.Shared/Services/StatisticalClearMLBuildJobFactory.cs
index e9395857..47493378 100644
--- a/src/Machine/src/Serval.Machine.Shared/Services/StatsiticalClearMLBuildJobFactory.cs
+++ b/src/Machine/src/Serval.Machine.Shared/Services/StatisticalClearMLBuildJobFactory.cs
@@ -35,7 +35,11 @@ public async Task<string> CreateJobScriptAsync(
                 + $"    'build_id': '{buildId}',\n"
                 + $"    'shared_file_uri': '{baseUri}',\n"
                 + $"    'shared_file_folder': '{folder}',\n"
-                + (buildOptions is not null ? $"    'build_options': '''{buildOptions}''',\n" : "")
+                + (
+                    buildOptions is not null
+                        ? $"    'build_options': '''{Convert.ToBase64String(Encoding.UTF8.GetBytes(buildOptions))}''',\n"
+                        : ""
+                )
                 + $"    'clearml': True\n"
                 + "}\n"
                 + "run(args)\n";
diff --git a/src/Machine/test/Serval.Machine.Shared.Tests/Services/NmtClearMLBuildJobFactoryTests.cs b/src/Machine/test/Serval.Machine.Shared.Tests/Services/NmtClearMLBuildJobFactoryTests.cs
index baa5cef5..e36dabc4 100644
--- a/src/Machine/test/Serval.Machine.Shared.Tests/Services/NmtClearMLBuildJobFactoryTests.cs
+++ b/src/Machine/test/Serval.Machine.Shared.Tests/Services/NmtClearMLBuildJobFactoryTests.cs
@@ -7,18 +7,20 @@ public class NmtClearMLBuildJobFactoryTests
     public async Task CreateJobScriptAsync_BuildOptions()
     {
         var env = new TestEnvironment();
+        const string BuildOptions = "{ \"max_steps\": \"10\" }";
+        string buildOptionsBase64 = Convert.ToBase64String(Encoding.UTF8.GetBytes(BuildOptions));
         string script = await env.BuildJobFactory.CreateJobScriptAsync(
             "engine1",
             "build1",
             "test_model",
             BuildStage.Train,
-            buildOptions: "{ \"max_steps\": \"10\" }"
+            buildOptions: BuildOptions
         );
         Assert.That(
             script,
             Is.EqualTo(
-                @"from machine.jobs.build_nmt_engine import run
-args = {
+                $@"from machine.jobs.build_nmt_engine import run
+args = {{
     'model_type': 'test_model',
     'engine_id': 'engine1',
     'build_id': 'build1',
@@ -26,9 +28,9 @@ public async Task CreateJobScriptAsync_BuildOptions()
     'trg_lang': 'eng_Latn',
     'shared_file_uri': 's3://bucket',
     'shared_file_folder': 'folder1/folder2',
-    'build_options': '''{ ""max_steps"": ""10"" }''',
+    'build_options': '''{buildOptionsBase64}''',
     'clearml': True
-}
+}}
 run(args)
 ".ReplaceLineEndings("\n")
             )
diff --git a/src/Machine/test/Serval.Machine.Shared.Tests/Usings.cs b/src/Machine/test/Serval.Machine.Shared.Tests/Usings.cs
index 4696e0f4..c1214b76 100644
--- a/src/Machine/test/Serval.Machine.Shared.Tests/Usings.cs
+++ b/src/Machine/test/Serval.Machine.Shared.Tests/Usings.cs
@@ -1,3 +1,4 @@
+global using System.Text;
 global using System.Text.Json;
 global using System.Text.Json.Nodes;
 global using Microsoft.Extensions.DependencyInjection;
@@ -6,7 +7,6 @@
 global using Microsoft.Extensions.Logging;
 global using Microsoft.Extensions.Options;
 global using NSubstitute;
-global using NSubstitute.ReceivedExtensions;
 global using NUnit.Framework;
 global using NUnit.Framework.Constraints;
 global using RichardSzalay.MockHttp;