diff --git a/build_mingw32 b/build_mingw32
index 46b86bb13..347550416 100755
--- a/build_mingw32
+++ b/build_mingw32
@@ -1,4 +1,6 @@
 MINGW=/opt/mingw32
 export PATH=$PATH:$MINGW/bin
+export CFLAGS="-march=pentium3 -mtune=generic -mpreferred-stack-boundary=5 -fno-tree-vectorize"
+export CXXFLAGS="$CFLAGS"
 cmake .. -DCMAKE_TOOLCHAIN_FILE=../cmake/modules/Win32Toolchain.cmake -DCMAKE_MODULE_PATH=`pwd`/../cmake/modules/
 
diff --git a/cmake/modules/Win32Toolchain.cmake b/cmake/modules/Win32Toolchain.cmake
index 84ebb4b92..3fd2612ac 100644
--- a/cmake/modules/Win32Toolchain.cmake
+++ b/cmake/modules/Win32Toolchain.cmake
@@ -2,9 +2,5 @@ SET(MINGW_PREFIX /opt/mingw32)
 
 SET(CMAKE_SYSTEM_PROCESSOR i686)
 
-SET(CMAKE_C_FLAGS "-march=i686 -mtune=generic")
-SET(CMAKE_CXX_FLAGS ${CMAKE_C_FLAGS})
-
-
 INCLUDE(MinGWCrossCompile)