1diff --git a/src/include/lwipopts.h b/src/include/lwipopts.h
2index 5ba123f..baf739e 100644
3--- a/src/include/lwipopts.h
4+++ b/src/include/lwipopts.h
5@@ -244,9 +244,13 @@
6 
7 #define SO_REUSE 1
8 
9+#ifndef FIONBIO
10 #define FIONBIO 0x5421 /* same as define in asm-generic/ioctls.h */
11+#endif
12 
13+#ifndef O_NONBLOCK
14 #define O_NONBLOCK 04000 /* same as define in bits/fcntl-linux.h */
15+#endif
16 
17 #define SIOCSHIWAT 1
18 
19