diff --git a/Libraries/LibC/errno_numbers.h b/Libraries/LibC/errno_numbers.h
index 7421967c92..b88f786576 100644
--- a/Libraries/LibC/errno_numbers.h
+++ b/Libraries/LibC/errno_numbers.h
@@ -71,4 +71,6 @@
 #define EPROTOTYPE 68
 #define EINPROGRESS 69
 #define ENOTHREAD 70
-#define EMAXERRNO 71
+#define EPROTO 71
+#define ENOTSUP 72
+#define EMAXERRNO 73