diff --git a/lib/libc/sys/sigreturn.2 b/lib/libc/sys/sigreturn.2
index aed6a9126cbd..4598f09c602b 100644
--- a/lib/libc/sys/sigreturn.2
+++ b/lib/libc/sys/sigreturn.2
@@ -43,7 +43,7 @@
 .Sh SYNOPSIS
 .In signal.h
 .Ft int
-.Fn sigreturn "ucontext_t *scp"
+.Fn sigreturn "const ucontext_t *scp"
 .Sh DESCRIPTION
 The
 .Fn sigreturn