diff --git a/libexec/rtld-elf/libmap.h b/libexec/rtld-elf/libmap.h
index a5ba143f211..6eeed43be05 100644
--- a/libexec/rtld-elf/libmap.h
+++ b/libexec/rtld-elf/libmap.h
@@ -2,7 +2,12 @@
  * $FreeBSD$
  */
 
+#ifndef LIBMAP_H
+#define	LIBMAP_H
+
 int	lm_init(const char *);
 void	lm_fini (void);
 char *	lm_find (const char *, const char *);
 char *	lm_findn (const char *, const char *, const size_t);
+
+#endif