diff --git a/include/wordexp.h b/include/wordexp.h
index ae219b6a1eae..02adc856c493 100644
--- a/include/wordexp.h
+++ b/include/wordexp.h
@@ -68,7 +68,7 @@ typedef struct {
 #define	WRDE_SYNTAX	6		/* shell syntax error */
 
 __BEGIN_DECLS
-int	wordexp(const char *, wordexp_t *, int);
+int	wordexp(const char * __restrict, wordexp_t * __restrict, int);
 void	wordfree(wordexp_t *);
 __END_DECLS