diff --git a/Wabbajack.CacheServer.Test/Wabbajack.CacheServer.Test.csproj b/Wabbajack.CacheServer.Test/Wabbajack.CacheServer.Test.csproj
index d3e0ed9f..ada745bb 100644
--- a/Wabbajack.CacheServer.Test/Wabbajack.CacheServer.Test.csproj
+++ b/Wabbajack.CacheServer.Test/Wabbajack.CacheServer.Test.csproj
@@ -86,10 +86,10 @@
   </ItemGroup>
   <ItemGroup>
     <PackageReference Include="MSTest.TestAdapter">
-      <Version>1.3.2</Version>
+      <Version>2.0.0</Version>
     </PackageReference>
     <PackageReference Include="MSTest.TestFramework">
-      <Version>1.3.2</Version>
+      <Version>2.0.0</Version>
     </PackageReference>
     <PackageReference Include="System.Reactive">
       <Version>4.2.0</Version>
diff --git a/Wabbajack.Lib/AInstaller.cs b/Wabbajack.Lib/AInstaller.cs
index a17a7983..7749dd1c 100644
--- a/Wabbajack.Lib/AInstaller.cs
+++ b/Wabbajack.Lib/AInstaller.cs
@@ -297,8 +297,11 @@ namespace Wabbajack.Lib
                 .Do(g =>
                 {
                     var required = g.Sum(i => i.Item2);
+                    var contains = g.Sum(folder =>
+                        Directory.EnumerateFiles(folder.Item1, "*", DirectoryEnumerationOptions.Recursive)
+                            .Sum(file => new FileInfo(file).Length));
                     var available = DriveInfo(g.Key).FreeBytesAvailable;
-                    if (required > available)
+                    if (required - contains > available)
                         throw new NotEnoughDiskSpaceException(
                             $"This modlist requires {required.ToFileSizeString()} on {g.Key} but only {available.ToFileSizeString()} is available.");
                 });