diff --git a/LibC/arpa/inet.h b/LibC/arpa/inet.h
index 7f3a8804e1..ee1de4fd7c 100644
--- a/LibC/arpa/inet.h
+++ b/LibC/arpa/inet.h
@@ -5,6 +5,8 @@
 
 __BEGIN_DECLS
 
+#define INET_ADDRSTRLEN 16
+
 const char* inet_ntop(int af, const void* src, char* dst, socklen_t);
 int inet_pton(int af, const char* src, void* dst);