diff --git a/inc/locfile.h b/inc/locfile.h
index 296c42d..a6d3c0b 100755
--- a/inc/locfile.h
+++ b/inc/locfile.h
@@ -703,6 +703,9 @@ extern	int	errno;
 #define DIRSEPSTR "/"
 #define DIRSEP '/'
 #define UNIXDIRSEP '/'
+/* system includes may already define MAXNAMLEN */
+#if !defined(MAXNAMLEN)
 #define MAXNAMLEN NAME_MAX
 #endif
+#endif