diff --git a/build.psm1 b/build.psm1
index 2900e1bc4f..9e9da60596 100644
--- a/build.psm1
+++ b/build.psm1
@@ -1855,7 +1855,7 @@ function Install-Dotnet {
         else {
             # dotnet-install.ps1 uses APIs that are not supported in .NET Core, so we run it with Windows PowerShell
             $fullPSPath = Join-Path -Path $env:windir -ChildPath "System32\WindowsPowerShell\v1.0\powershell.exe"
-            $fullDotnetInstallPath = Join-Path -Path $PWD.Path -ChildPath $installScript
+            $fullDotnetInstallPath = Join-Path -Path (Convert-Path -Path $PWD.Path) -ChildPath $installScript
 
             if ($Version) {
                 $psArgs = @('-NoLogo', '-NoProfile', '-File', $fullDotnetInstallPath, '-Version', $Version, '-Quality', $Quality)