diff --git a/tools/windows/clvars.bat b/tools/windows/clvars.bat
index c08ed17..4f63bd1 100644
--- a/tools/windows/clvars.bat
+++ b/tools/windows/clvars.bat
@@ -34,4 +34,4 @@ set WARNINGS=%WARNINGS% -wd4996
 REM we use sprintf
 set DEFINES=-D_CRT_SECURE_NO_WARNINGS
 
-set CLFLAGS=%DEFINES% %WARNINGS%
+set CLFLAGS=-Od -Z7 %DEFINES% %WARNINGS% -Debug