diff --git a/src/LibHac.Nand/LibHac.Nand.csproj b/src/LibHac.Nand/LibHac.Nand.csproj
index 789a0132..80b4ddab 100644
--- a/src/LibHac.Nand/LibHac.Nand.csproj
+++ b/src/LibHac.Nand/LibHac.Nand.csproj
@@ -2,6 +2,7 @@
 
   <PropertyGroup>
     <TargetFrameworks>netcoreapp2.1;net46</TargetFrameworks>
+    <LangVersion>7.3</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
diff --git a/src/hactoolnet/CliParser.cs b/src/hactoolnet/CliParser.cs
index 52c090cb..03394f98 100644
--- a/src/hactoolnet/CliParser.cs
+++ b/src/hactoolnet/CliParser.cs
@@ -46,6 +46,7 @@ namespace hactoolnet
             new CliOption("normaldir", 1, (o, a) => o.NormalDir = a[0]),
             new CliOption("securedir", 1, (o, a) => o.SecureDir = a[0]),
             new CliOption("logodir", 1, (o, a) => o.LogoDir = a[0]),
+            new CliOption("repack", 1, (o, a) => o.RepackSource = a[0]),
             new CliOption("listapps", 0, (o, a) => o.ListApps = true),
             new CliOption("listtitles", 0, (o, a) => o.ListTitles = true),
             new CliOption("listncas", 0, (o, a) => o.ListNcas = true),
@@ -235,6 +236,7 @@ namespace hactoolnet
             sb.AppendLine("  --sign               Sign the save file. (Requires device_key in key file)");
             sb.AppendLine("  --trim               Trim garbage data in the save file. (Requires device_key in key file)");
             sb.AppendLine("  --listfiles          List files in save file.");
+            sb.AppendLine("  --repack <dir>       Replaces the contents of the save data with the specified directory.");
             sb.AppendLine("  --replacefile <filename in save> <file> Replaces a file in the save data");
             sb.AppendLine("NDV0 (Delta) options:");
             sb.AppendLine("                       Input delta patch can be a delta NCA file or a delta fragment file.");
diff --git a/src/hactoolnet/Options.cs b/src/hactoolnet/Options.cs
index c99db2c4..353c5253 100644
--- a/src/hactoolnet/Options.cs
+++ b/src/hactoolnet/Options.cs
@@ -39,6 +39,7 @@ namespace hactoolnet
         public string LogoDir;
         public string ReplaceFileSource;
         public string ReplaceFileDest;
+        public string RepackSource;
         public bool ListApps;
         public bool ListTitles;
         public bool ListNcas;
diff --git a/src/hactoolnet/ProcessSave.cs b/src/hactoolnet/ProcessSave.cs
index d111def5..5d9488fa 100644
--- a/src/hactoolnet/ProcessSave.cs
+++ b/src/hactoolnet/ProcessSave.cs
@@ -16,6 +16,8 @@ namespace hactoolnet
         {
             using (var file = new LocalStorage(ctx.Options.InFile, FileAccess.ReadWrite))
             {
+                bool signNeeded = ctx.Options.SignSave;
+
                 var save = new SaveDataFileSystem(ctx.Keyset, file, ctx.Options.IntegrityLevel, true);
 
                 if (ctx.Options.Validate)
@@ -30,52 +32,61 @@ namespace hactoolnet
 
                 if (ctx.Options.DebugOutDir != null)
                 {
-                    // todo
                     string dir = ctx.Options.DebugOutDir;
 
                     ExportSaveDebug(ctx, dir, save);
                 }
 
-                if (ctx.Options.ReplaceFileDest != null && ctx.Options.ReplaceFileSource != null)
+                try
                 {
-                    string destFilename = ctx.Options.ReplaceFileDest;
-                    if (!destFilename.StartsWith("/")) destFilename = '/' + destFilename;
-
-                    using (IFile inFile = new LocalFile(ctx.Options.ReplaceFileSource, OpenMode.Read))
+                    if (ctx.Options.ReplaceFileDest != null && ctx.Options.ReplaceFileSource != null)
                     {
-                        using (IFile outFile = save.OpenFile(destFilename, OpenMode.ReadWrite))
+                        string destFilename = ctx.Options.ReplaceFileDest;
+                        if (!destFilename.StartsWith("/")) destFilename = '/' + destFilename;
+
+                        using (IFile inFile = new LocalFile(ctx.Options.ReplaceFileSource, OpenMode.Read))
                         {
-                            if (inFile.GetSize() != outFile.GetSize())
+                            using (IFile outFile = save.OpenFile(destFilename, OpenMode.ReadWrite))
                             {
-                                outFile.SetSize(inFile.GetSize());
+                                if (inFile.GetSize() != outFile.GetSize())
+                                {
+                                    outFile.SetSize(inFile.GetSize());
+                                }
+
+                                inFile.CopyTo(outFile, ctx.Logger);
+
+                                ctx.Logger.LogMessage($"Replaced file {destFilename}");
                             }
-
-                            inFile.CopyTo(outFile, ctx.Logger);
-
-                            ctx.Logger.LogMessage($"Replaced file {destFilename}");
                         }
+
+                        signNeeded = true;
                     }
 
-                    if (save.Commit(ctx.Keyset))
+                    if (ctx.Options.RepackSource != null)
                     {
-                        ctx.Logger.LogMessage("Successfully signed save file");
-                    }
-                    else
-                    {
-                        ctx.Logger.LogMessage("ERROR: Unable to sign save file. Do you have all the required keys?");
-                    }
+                        var source = new LocalFileSystem(ctx.Options.RepackSource);
 
-                    return;
+                        save.CleanDirectoryRecursively("/");
+                        save.Commit(ctx.Keyset);
+                        source.CopyFileSystem(save);
+
+                        signNeeded = true;
+                    }
+                }
+                finally
+                {
+                    save.Commit(ctx.Keyset);
                 }
 
-                if (ctx.Options.SignSave || ctx.Options.TrimSave)
+                if (ctx.Options.TrimSave)
                 {
-                    if (ctx.Options.TrimSave)
-                    {
-                        save.FsTrim();
-                        ctx.Logger.LogMessage("Trimmed save file");
-                    }
+                    save.FsTrim();
+                    signNeeded = true;
+                    ctx.Logger.LogMessage("Trimmed save file");
+                }
 
+                if (signNeeded)
+                {
                     if (save.Commit(ctx.Keyset))
                     {
                         ctx.Logger.LogMessage("Successfully signed save file");
@@ -90,14 +101,14 @@ namespace hactoolnet
 
                 if (ctx.Options.ListFiles)
                 {
-                    foreach (DirectoryEntry entry in save.EnumerateEntries().Where(x => x.Type == DirectoryEntryType.File))
+                    foreach (DirectoryEntry entry in save.EnumerateEntries())
                     {
                         ctx.Logger.LogMessage(entry.FullPath);
                     }
                 }
 
                 ctx.Logger.LogMessage(save.Print());
-                //ctx.Logger.LogMessage(PrintFatLayout(save));
+                //ctx.Logger.LogMessage(PrintFatLayout(save.SaveDataFileSystemCore));
             }
         }