diff --git a/Minecraft.Client/Common/Postbuilds/Orbis-postbuild.ps1 b/Minecraft.Client/Common/Postbuilds/Orbis-postbuild.ps1
index 3b9aed05..434b8359 100644
--- a/Minecraft.Client/Common/Postbuilds/Orbis-postbuild.ps1
+++ b/Minecraft.Client/Common/Postbuilds/Orbis-postbuild.ps1
@@ -128,7 +128,9 @@ if (-not (Test-Path $genGp4)) {
 } else {
     Write-Host "Orbis Postbuild: Generating GP4..."
     $proc = Start-Process -FilePath $genGp4 -ArgumentList $pkgSrc `
-    -NoNewWindow -Wait -PassThru
+        -WorkingDirectory (Split-Path $pkgSrc -Parent) `
+        -NoNewWindow -Wait -PassThru
+
     if ($proc.ExitCode -ne 0) {
         Write-Host "Orbis Postbuild ERROR: gengp4_app.exe failed with exit code $($proc.ExitCode)"
         return