diff --git a/win/build-deps.cmd b/win/build-deps.cmd
index e01cd62d65..040d87b9f0 100644
--- a/win/build-deps.cmd
+++ b/win/build-deps.cmd
@@ -98,7 +98,8 @@ IF NOT DEFINED IFCOS_NUM_BUILD_PROCS set IFCOS_NUM_BUILD_PROCS=%NUMBER_OF_PROCES
 :: For subroutines
 REM /clp:ErrorsOnly;WarningsOnly
 :: Note BUILD_TYPE not passed, Clean e.g. wouldn't delete the installed files.
-set MSBUILD_CMD=MSBuild.exe /nologo /m:%IFCOS_NUM_BUILD_PROCS%
+set MSBUILD_MULTIPROC=/m /p:CL_MPCount=%IFCOS_NUM_BUILD_PROCS% /p:UseMultiToolTask=true /p:EnforceProcessCountAcrossBuilds=true
+set MSBUILD_CMD=MSBuild.exe /nologo %MSBUILD_MULTIPROC%
 
 echo.
 
diff --git a/win/install-ifcopenshell.bat b/win/install-ifcopenshell.bat
index 6c46574819..ee6ed3b53c 100755
--- a/win/install-ifcopenshell.bat
+++ b/win/install-ifcopenshell.bat
@@ -58,7 +58,8 @@ call cecho.cmd 0 13 "* IFCOS_NUM_BUILD_PROCS`t= %IFCOS_NUM_BUILD_PROCS%"
 echo.
 
 call cecho.cmd 0 13 "Installing %VS_PLATFORM% %BUILD_CFG% %PROJECT_NAME%"
-cmake --build ..\%BUILD_DIR% --target INSTALL -- /nologo /m:%IFCOS_NUM_BUILD_PROCS% /p:Platform=%VS_PLATFORM% ^
+set MSBUILD_MULTIPROC=/m /p:CL_MPCount=%IFCOS_NUM_BUILD_PROCS% /p:UseMultiToolTask=true /p:EnforceProcessCountAcrossBuilds=true
+cmake --build ..\%BUILD_DIR% --target INSTALL -- /nologo %MSBUILD_MULTIPROC% /p:Platform=%VS_PLATFORM% ^
     /p:Configuration=%BUILD_CFG% %3 %4 %5 %6 %7 %8 %9
 IF NOT %ERRORLEVEL%==0 GOTO :Error