diff --git a/docs/WASI-api.md b/docs/WASI-api.md
index 6cf2886e28..9e82b43e43 100644
--- a/docs/WASI-api.md
+++ b/docs/WASI-api.md
@@ -1594,7 +1594,10 @@ Used by many functions in this API.
 
 As in POSIX, three file descriptor numbers are provided to instances
 on startup -- 0, 1, and 2, (a.k.a. `STDIN_FILENO`, `STDOUT_FILENO`,
-and `STDERR_FILENO`).
+and `STDERR_FILENO`). Starting at 3 follow a possibly-entry sequence
+of preopened file descriptors provided by the host environment;
+information about these may be obtained through
+[`__wasi_fd_prestat_get()`](#fd_prestat_get).
 
 Other than these, WASI implementations are not required to allocate
 new file descriptors in ascending order.