diff --git a/build.psm1 b/build.psm1
index 1b4559af3f6..554ed1036b2 100644
--- a/build.psm1
+++ b/build.psm1
@@ -265,12 +265,12 @@ function Start-PSBuild {
     }
 
     if ($Clean) {
-        Write-Log "Cleaning your working directory. You can also do it with 'git clean -fdx --exclude .vs/PowerShell/v15/Server/sqlite3'"
+        Write-Log "Cleaning your working directory. You can also do it with 'git clean -fdX --exclude .vs/PowerShell/v15/Server/sqlite3'"
         Push-Location $PSScriptRoot
         try {
             # Excluded sqlite3 folder is due to this Roslyn issue: https://github.com/dotnet/roslyn/issues/23060
             # Excluded src/Modules/nuget.config as this is required for release build.
-            git clean -fdx --exclude .vs/PowerShell/v15/Server/sqlite3 --exclude src/Modules/nuget.config
+            git clean -fdX --exclude .vs/PowerShell/v15/Server/sqlite3 --exclude src/Modules/nuget.config
         } finally {
             Pop-Location
         }