diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index ccd64d6..203f985 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -6763,12 +6763,11 @@ os_sched_getaffinity_impl(PyObject *module, pid_t pid)
 
 
 /* AIX uses /dev/ptc but is otherwise the same as /dev/ptmx */
-/* IRIX has both /dev/ptc and /dev/ptmx, use ptmx */
 #if defined(HAVE_DEV_PTC) && !defined(HAVE_DEV_PTMX)
-#define DEV_PTY_FILE "/dev/ptc"
-#define HAVE_DEV_PTMX
+#  define DEV_PTY_FILE "/dev/ptc"
+#  define HAVE_DEV_PTMX
 #else
-#define DEV_PTY_FILE "/dev/ptmx"
+#  define DEV_PTY_FILE "/dev/ptmx"
 #endif
 
 #if defined(HAVE_OPENPTY) || defined(HAVE_FORKPTY) || defined(HAVE_DEV_PTMX)