diff --git a/mswin32/Build.bat b/mswin32/Build.bat
index 737fd5567..c389d9018 100644
--- a/mswin32/Build.bat
+++ b/mswin32/Build.bat
@@ -1,4 +1,5 @@
 @echo off
+setlocal EnableDelayedExpansion
 set TARGET=%1
 set VCCONFIG=%2
 
@@ -25,9 +26,9 @@ for /f "usebackq delims=" %%i in ("%TEMP%\vspath.txt") do call "%%i\VC\Auxiliary
 set VS_GENERATOR=Visual Studio 17 2022
 for /f "usebackq delims=" %%v in ("%TEMP%\vsver.txt") do (
   set VSVER=%%v
-  if "%%v:~0,2%%" == "16" set VS_GENERATOR=Visual Studio 16 2019
-  if "%%v:~0,2%%" == "17" set VS_GENERATOR=Visual Studio 17 2022
-  if "%%v:~0,2%%" == "18" set VS_GENERATOR=Visual Studio 18 2026
+  if "!VSVER:~0,2!" == "16" set VS_GENERATOR=Visual Studio 16 2019
+  if "!VSVER:~0,2!" == "17" set VS_GENERATOR=Visual Studio 17 2022
+  if "!VSVER:~0,2!" == "18" set VS_GENERATOR=Visual Studio 18 2026
 )
 
 :generator_set