diff --git a/slirp/slirp.h b/slirp/slirp.h
index 964d5e19b7fa965ab8452fe71a5a868e121f4452..fb55ad9c32f8238d628045994fe7d08a261fa2af 100644
--- a/slirp/slirp.h
+++ b/slirp/slirp.h
@@ -33,6 +33,7 @@ typedef char *caddr_t;
 #else
 # define ioctlsocket ioctl
 # define closesocket(s) close(s)
+# define O_BINARY 0
 #endif
 
 #include <sys/types.h>
diff --git a/slirp/tftp.c b/slirp/tftp.c
index 90526625c019dcdf8eab00058a462f3096f3ad07..c9946d6bf2111bc5c72d55e33f47a7f706e40561 100644
--- a/slirp/tftp.c
+++ b/slirp/tftp.c
@@ -103,7 +103,7 @@ static int tftp_read_data(struct tftp_session *spt, u_int16_t block_nr,
   int fd;
   int bytes_read = 0;
 
-  fd = open(spt->filename, O_RDONLY);
+  fd = open(spt->filename, O_RDONLY | O_BINARY);
 
   if (fd < 0) {
     return -1;