diff --git a/include/ntapi/nt_socket.h b/include/ntapi/nt_socket.h
index 57b0801..4c32132 100644
--- a/include/ntapi/nt_socket.h
+++ b/include/ntapi/nt_socket.h
@@ -69,7 +69,7 @@
 #define NT_AF_DATAKIT		(0x0009u)
 #define NT_AF_CCITT		(0x000Au)
 #define NT_AF_SNA		(0x000Bu)
-#define NT_AF_DECnet		(0x000Cu)
+#define NT_AF_DECNET		(0x000Cu)
 #define NT_AF_DLI		(0x000Du)
 #define NT_AF_LAT		(0x000Eu)
 #define NT_AF_HYLINK		(0x000Fu)