diff --git a/Source/HBIOS/Build.cmd b/Source/HBIOS/Build.cmd
index 52660c54..d315afa8 100644
--- a/Source/HBIOS/Build.cmd
+++ b/Source/HBIOS/Build.cmd
@@ -1,4 +1,9 @@
 @echo off
+
+set TOOLS=../../Tools
+
+setlocal & cd .\Forth && call Build || exit /b 1 & endlocal
+
 setlocal
 
 PowerShell .\Build.ps1 %*