diff --git a/include/ldap_cdefs.h b/include/ldap_cdefs.h
index 87a6ca4d26..cd86d77f97 100644
--- a/include/ldap_cdefs.h
+++ b/include/ldap_cdefs.h
@@ -31,6 +31,10 @@
 #	define LDAP_STRING(x)	#x /* stringify without expanding x */
 #	define LDAP_XSTRING(x)	LDAP_STRING(x) /* expand x, then stringify */
 
+#ifndef LDAP_CONST
+#	define LDAP_CONST	const
+#endif
+
 #else /* no prototypes */
 
 	/* traditional C */
@@ -38,6 +42,10 @@
 #	define LDAP_CONCAT(x,y)	x/**/y
 #	define LDAP_STRING(x)	"x"
 
+#ifndef LDAP_CONST
+#	define LDAP_CONST	/* no const */
+#endif
+
 #endif /* no prototypes */