diff --git a/include/portable.nt b/include/portable.nt
index 080089649f..a216f877ea 100644
--- a/include/portable.nt
+++ b/include/portable.nt
@@ -725,9 +725,9 @@ typedef signed int ssize_t;
 
 /* begin of postamble */
 
-#ifndef __NEED_PROTOTYPES
+#ifndef LDAP_NEED_PROTOTYPES
 /* force LDAP_P to always include prototypes */
-#define __NEED_PROTOTYPES 1 
+#define LDAP_NEED_PROTOTYPES 1 
 #endif
 
 #ifdef HAVE_STDDEF_H