diff --git a/scripts/Windows/OS/Install.ps1 b/scripts/Windows/OS/Install.ps1
index 3e824e80..3f4390d6 100644
--- a/scripts/Windows/OS/Install.ps1
+++ b/scripts/Windows/OS/Install.ps1
@@ -176,7 +176,7 @@ $null = New-Module {
                     #>
                     function Deploy-SoftwareAction {
                         param(
-                            [InstallerAction] $Action = $null
+                            [Nullable[InstallerAction]] $Action = $null
                         )
 
                         [bool] $install = $null;