diff --git a/winsup/bz2lib/ChangeLog b/winsup/bz2lib/ChangeLog
index 44102bbcf..c703a6e76 100644
--- a/winsup/bz2lib/ChangeLog
+++ b/winsup/bz2lib/ChangeLog
@@ -1,3 +1,8 @@
+Wed Apr 18 23:54:53 2001  Christopher Faylor <cgf@cygnus.com>
+
+	* Makefile.in: Add -U_WIN32 to CFLAGS compile line to avoid
+	inappropriate Windows-isms.
+
 Wed Apr 18 15:58:28 2001  Christopher Faylor <cgf@cygnus.com>
 
 	Initial checkin from net sources.
diff --git a/winsup/bz2lib/Makefile.in b/winsup/bz2lib/Makefile.in
index 8494a9f67..622445d23 100644
--- a/winsup/bz2lib/Makefile.in
+++ b/winsup/bz2lib/Makefile.in
@@ -48,8 +48,8 @@ include $(srcdir)/../Makefile.common
 
 MINGW_INCLUDES:=-I. -I$(srcdir) -I$(mingw_source)/include -I$(w32api_include) -I$(updir)/bz2lib
 
-MINGW_CXXFLAGS:=-MMD $(CXXFLAGS) -mno-cygwin $(MINGW_INCLUDES) -mwindows
-MINGW_CFLAGS:=-MMD $(CFLAGS) -mno-cygwin $(MINGW_INCLUDES) -mwindows
+MINGW_CXXFLAGS:=-MMD $(CXXFLAGS) -mno-cygwin $(MINGW_INCLUDES) -mwindows -U_WIN32
+MINGW_CFLAGS:=-MMD $(CFLAGS) -mno-cygwin $(MINGW_INCLUDES) -mwindows -U_WIN32
 
 ZLIB:=zlib/libzcygw.a
 BZ2LIB:=$(bupdir)/bz2lib/libbz2.a