diff --git a/setup.c b/setup.c
index c3301f5ab..6652c1dff 100644
--- a/setup.c
+++ b/setup.c
@@ -1691,11 +1691,20 @@ const char *resolve_gitdir_gently(const char *suspect, int *return_error_code)
 /* if any standard file descriptor is missing open it to /dev/null */
 void sanitize_stdfds(void)
 {
-	int fd = xopen("/dev/null", O_RDWR);
-	while (fd < 2)
-		fd = xdup(fd);
-	if (fd > 2)
-		close(fd);
+	/*
+	 * MontaukOS: nothing to sanitize, and nothing to sanitize it with.
+	 *
+	 * This guards against being started with 0/1/2 closed, so that a
+	 * later open() cannot land on a standard descriptor and have die()
+	 * write its message into a data file. On MontaukOS that cannot
+	 * happen: the kernel gives every process the terminal on 0/1/2 (the
+	 * libc routes those descriptors to SYS_PUTCHAR/SYS_GETCHAR rather
+	 * than to any handle), and a process is spawned, never forked with a
+	 * doctored descriptor table.
+	 *
+	 * The upstream body cannot run in any case -- there is no /dev/null,
+	 * so xopen() would die here and take every git invocation with it.
+	 */
 }
 
 int daemonize(void)