diff --git a/ThunderstoreCLI/Commands/BuildCommand.cs b/ThunderstoreCLI/Commands/BuildCommand.cs
index 3cdbeac..24ad279 100644
--- a/ThunderstoreCLI/Commands/BuildCommand.cs
+++ b/ThunderstoreCLI/Commands/BuildCommand.cs
@@ -225,7 +225,7 @@ public static bool AddPathToArchivePlan(ArchivePlan plan, string sourcePath, str
 
             foreach (string filename in Directory.EnumerateFiles(basePath, "*.*", SearchOption.AllDirectories))
             {
-                var targetPath = FormatArchivePath($"{destDirectory}{filename[(basePath.Length + 1)..]}");
+                var targetPath = FormatArchivePath($"{destDirectory}{Path.GetRelativePath(basePath, filename)}");
                 plan.AddPlan(targetPath, () => File.ReadAllBytes(filename));
             }
             return true;