diff --git a/Userland/Libraries/LibC/arpa/inet.h b/Userland/Libraries/LibC/arpa/inet.h
index 8949ab7f9d..c9022663fd 100644
--- a/Userland/Libraries/LibC/arpa/inet.h
+++ b/Userland/Libraries/LibC/arpa/inet.h
@@ -35,6 +35,7 @@
 __BEGIN_DECLS
 
 #define INET_ADDRSTRLEN 16
+#define INET6_ADDRSTRLEN 46
 
 const char* inet_ntop(int af, const void* src, char* dst, socklen_t);
 int inet_pton(int af, const char* src, void* dst);