diff --git a/man3/swab.3 b/man3/swab.3
index b68d698d7..700d2d5f4 100644
--- a/man3/swab.3
+++ b/man3/swab.3
@@ -36,7 +36,8 @@ swab \- swap adjacent bytes
 .BR "#define _XOPEN_SOURCE" "       /* See feature_test_macros(7) */"
 .B #include <unistd.h>
 .PP
-.BI "void swab(const void *" from ", void *" to ", ssize_t " n );
+.BI "void swab(const void *restrict " from ", void *restrict " to \
+", ssize_t " n );
 .fi
 .SH DESCRIPTION
 The