--- a/src/include/lwip/arch.h
+++ b/src/include/lwip/arch.h
@@ -208,6 +208,12 @@ extern "C" {
 extern int errno;
 #endif
 
+#else
+
+#include <errno.h>
+/* errno codes which are not defined in Genode libc's errno.h */
+#define ENSRNOTFOUND 163  /* Domain name not found */
+
 #endif /* LWIP_PROVIDE_ERRNO */
 
 #ifdef __cplusplus