diff --git a/build.sh b/build.sh
index 4ecfe7e9b24e3e92363aea00aa532e921b91d98f..4cc5b8b97c8908bf8378757d088162efabe8e667 100755
--- a/build.sh
+++ b/build.sh
@@ -741,8 +741,6 @@ build_mac()
 build_win32()
 {
     export CPPFLAGS="-D_WIN32_WINDOWS=0x0410 $CPPFLAGS"
-    export CFLAGS="-mms-bitfields $CFLAGS"
-    export CXXFLAGS="-mms-bitfields $CXXFLAGS"
 
     prepare_mingw || failure
     build_mingw || failure