diff --git a/util/cbfstool/Makefile.inc b/util/cbfstool/Makefile.inc
index ad2e120..f9aef2e 100644
--- a/util/cbfstool/Makefile.inc
+++ b/util/cbfstool/Makefile.inc
@@ -15,6 +15,10 @@
 
 CBFSTOOLFLAGS=-DCOMPACT -g
 
+ifeq ($(shell uname -s | cut -c-7 2>/dev/null), MINGW32)
+CBFSTOOLFLAGS+=-mno-ms-bitfields
+endif
+
 $(objutil)/cbfstool:
 	mkdir -p $@