diff --git a/man3/setbuf.3 b/man3/setbuf.3
index 5e5d57f89..0d7cca8f9 100644
--- a/man3/setbuf.3
+++ b/man3/setbuf.3
@@ -229,7 +229,7 @@ int
 main(void)
 {
     char buf[BUFSIZ];
-    setbuf(stdin, buf);
+    setbuf(stdout, buf);
     printf("Hello, world!\en");
     return 0;
 }