diff --git a/glib/gspawn.c b/glib/gspawn.c
index d4644f164..7a2618489 100644
--- a/glib/gspawn.c
+++ b/glib/gspawn.c
@@ -854,6 +854,8 @@ g_spawn_async_with_pipes (const gchar          *working_directory,
  * windows on the right screen, you may want to use #GdkAppLaunchContext,
  * #GAppLaunchContext, or set the `DISPLAY` environment variable.
  *
+ * On Windows, sharing the same FD for @stdout_fd and @stderr_fd is not supported.
+ *
  * Returns: %TRUE on success, %FALSE if an error was set
  *
  * Since: 2.68
@@ -936,6 +938,8 @@ g_spawn_async_with_pipes_and_fds (const gchar           *working_directory,
  * Identical to g_spawn_async_with_pipes_and_fds() but with `n_fds` set to zero,
  * so no FD assignments are used.
  *
+ * On Windows, sharing the same FD for @stdout_fd and @stderr_fd is not supported.
+ *
  * Returns: %TRUE on success, %FALSE if an error was set
  *
  * Since: 2.58
diff --git a/glib/tests/spawn-singlethread.c b/glib/tests/spawn-singlethread.c
index 7711ba8fe..159e8c34a 100644
--- a/glib/tests/spawn-singlethread.c
+++ b/glib/tests/spawn-singlethread.c
@@ -196,7 +196,9 @@ test_spawn_async_with_fds (void)
     { NO_FD, NO_FD, NO_FD },       /* Test with no fds passed */
     { NO_FD, FD_NEGATIVE, NO_FD }, /* Test another negative fd value */
     { PIPE, PIPE, PIPE },          /* Test with unique fds passed */
+#ifndef G_OS_WIN32
     { NO_FD, PIPE, STDOUT_PIPE },  /* Test the same fd for stdout + stderr */
+#endif
   };
 
   arg = g_strdup_printf ("thread %d", tnum);