diff --git a/man3/mbstowcs.3 b/man3/mbstowcs.3
index 03078c81d..c79ba9044 100644
--- a/man3/mbstowcs.3
+++ b/man3/mbstowcs.3
@@ -21,7 +21,8 @@ mbstowcs \- convert a multibyte string to a wide-character string
 .nf
 .B #include <stdlib.h>
 .PP
-.BI "size_t mbstowcs(wchar_t *" dest ", const char *" src ", size_t " n );
+.BI "size_t mbstowcs(wchar_t *restrict " dest ", const char *restrict " src ,
+.BI "                size_t " n );
 .fi
 .SH DESCRIPTION
 If