diff --git a/lib/curl_setup_once.h b/lib/curl_setup_once.h
index f549d25ce5..0bba02348d 100644
--- a/lib/curl_setup_once.h
+++ b/lib/curl_setup_once.h
@@ -337,9 +337,6 @@ typedef unsigned int bit;
 #define ETIMEDOUT        WSAETIMEDOUT
 #undef  ECONNREFUSED     /* override definition in errno.h */
 #define ECONNREFUSED     WSAECONNREFUSED
-#ifndef ENAMETOOLONG     /* possible previous definition in errno.h */
-#define ENAMETOOLONG     WSAENAMETOOLONG
-#endif
 #endif
 
 /*