diff --git a/build.fsx b/build.fsx
index 98350e2..ff2577e 100644
--- a/build.fsx
+++ b/build.fsx
@@ -13,6 +13,8 @@ let runs = 10
 let compilerForkToTest = @"https://github.com/forki/visualfsharp"
 let compilerHashes = ["71c8798e19d6e15d3e6a98c80da658aa5ed2c630"; "1bf329fa06b7e2e4d4ceab545b0e059e72be3e1c"]
 
+let additionalFlags = "--typecheckonly"
+
 let projects =
     [ "Paket", "https://github.com/fsprojects/Paket.git", "build.cmd", "src/Paket.Core", """-o:obj\Release\Paket.Core.dll -g --debug:pdbonly --noframework --define:TRACE --doc:..\..\bin\Paket.Core.XML --optimize+ -r:..\..\packages\Chessie\lib\net40\Chessie.dll -r:..\..\packages\FSharp.Core\lib\net40\FSharp.Core.dll -r:..\..\packages\Mono.Cecil\lib\net45\Mono.Cecil.dll -r:..\..\packages\Mono.Cecil\lib\net45\Mono.Cecil.Mdb.dll -r:..\..\packages\Mono.Cecil\lib\net45\Mono.Cecil.Pdb.dll -r:..\..\packages\Mono.Cecil\lib\net45\Mono.Cecil.Rocks.dll -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\mscorlib.dll" -r:..\..\packages\Newtonsoft.Json\lib\net45\Newtonsoft.Json.dll -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Configuration.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Core.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Data.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Data.Linq.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.IO.Compression.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.IO.Compression.FileSystem.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Numerics.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Security.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Xml.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.5\System.Xml.Linq.dll" --target:library --warn:3 --warnaserror:76 --vserrors --validate-type-providers --LCID:1033 --utf8output --fullpaths --flaterrors --subsystemversion:6.00 --highentropyva+ --sqmsessionguid:bcb8c335-41a6-4173-9636-2335b6448248 ..\..\paket-files\fsprojects\FSharp.TypeProviders.StarterPack\src\AssemblyReader.fs ..\..\paket-files\fsharp\FAKE\src\app\FakeLib\Globbing\Globbing.fs Async.fs AssemblyInfo.fs CustomAssemblyInfo.fs Domain.fs Constants.fs Logging.fsi Logging.fs Utils.fs SemVer.fs VersionRange.fs Xml.fs GitCommandHelper.fs GitHandling.fs PlatformDetection.fs ConfigFile.fs Cache.fs Cultures.fs PackageSources.fs FrameworkHandling.fs PlatformMatching.fs Requirements.fs ModuleResolver.fs RemoteDownload.fs RemoteUpload.fs PackageResolver.fs Nuspec.fs InstallModel.fs ReferencesFile.fs SolutionFile.fs Nuget.fs NuGetV3.fs NuGetV2.fs DependenciesTypes.fs DependenciesFileParser.fs LockFile.fs TemplateFile.fs ProjectFile.fs DependenciesFile.fs LocalFile.fs DependencyChangeDetection.fs GarbageCollection.fs RestoreProcess.fs BindingRedirects.fs NupkgWriter.fs ProcessOptions.fs PackagesConfigFile.fs DependencyModel.fs InstallProcess.fs UpdateProcess.fs RemoveProcess.fs AddProcess.fs PackageMetaData.fs PackageProcess.fs Environment.fs Releases.fs Simplifier.fs VSIntegration.fs NugetConvert.fs FindOutdated.fs FindReferences.fs PublicAPI.fs ScriptGeneration.fs"""
       "FSharpx.Collections", "https://github.com/fsprojects/FSharpx.Collections.git", "build.cmd", "src/FSharpx.Collections" , """-o:obj\Debug\FSharpx.Collections.dll -g --debug:full --noframework --optimize- --tailcalls- -r:..\..\packages\FSharp.Core\lib\net40\FSharp.Core.dll -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\mscorlib.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.Core.dll" -r:"C:\Program Files (x86)\Reference Assemblies\Microsoft\Framework\.NETFramework\v4.0\System.dll" --target:library --warn:3 --warnaserror:76 --vserrors --validate-type-providers --LCID:1033 --utf8output --fullpaths --flaterrors --highentropyva- --sqmsessionguid:69dfdfc7-1aa9-4121-9408-d55ff440afae AssemblyInfo.fs Exceptions.fs Interfaces.fs Infrastructure.fs LazyList.fsi LazyList.fs ResizeArray.fsi ResizeArray.fs Collections.fs Deque.fsi Deque.fs DList.fsi DList.fs ByteString.fs CircularBuffer.fs PriorityQueue.fs NonEmptyList.fs RandomAccessList.fsi RandomAccessList.fs Queue.fsi Queue.fs Literals.fs PersistentVector.fsi PersistentVector.fs PersistentHashMap.fs"""
@@ -75,7 +77,7 @@ Target "RunPerfTests" (fun _ ->
                 let result = 
                     ExecProcess (fun info -> 
                         info.FileName <- compilerExe
-                        info.Arguments <- args
+                        info.Arguments <- additionalFlags + " " + args
                         info.WorkingDirectory <- Path.Combine(projectDir name,dir)) System.TimeSpan.MaxValue
                 if result <> 0 then failwithf "Error during compile test of %s" name
                 times.Add((name,run),sw.ElapsedMilliseconds)