diff --git a/src/libc/ansi/stdio/stdaux.c b/src/libc/ansi/stdio/stdaux.c
index dd7508b5..86267b61 100644
--- a/src/libc/ansi/stdio/stdaux.c
+++ b/src/libc/ansi/stdio/stdaux.c
@@ -3,9 +3,36 @@
 /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
 #include <stdio.h>
 #include <libc/file.h>
+#include <libc/djctx.h>
 
-FILE __dj_stdaux = {
+FILE __dj_stdaux;
+
+static const FILE __dj_stdaux_init = {
   0, 0, 0, 0,
   _IORW | _IONBF,
   3
 };
+
+struct ste_state {
+  FILE __dj_stdaux;
+};
+
+static struct ste_state *ste;
+
+static const struct ste_state sinit =
+{
+  .__dj_stdaux = __dj_stdaux_init,
+};
+
+static void ste_pre(void)
+{
+#define _SV(x) ste->x = x
+  _SV(__dj_stdaux);
+}
+static void ste_post(void)
+{
+#define _RS(x) x = ste->x
+  _RS(__dj_stdaux);
+}
+DJ64_DEFINE_SWAPPABLE_CONTEXT2(ste_state, ste, sinit,
+    ste_pre(), ste_post());
diff --git a/src/libc/ansi/stdio/stderr.c b/src/libc/ansi/stdio/stderr.c
index a29280bb..2ac486e7 100644
--- a/src/libc/ansi/stdio/stderr.c
+++ b/src/libc/ansi/stdio/stderr.c
@@ -2,9 +2,36 @@
 /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
 #include <stdio.h>
 #include <libc/file.h>
+#include <libc/djctx.h>
 
-FILE __dj_stderr = {
+FILE __dj_stderr;
+
+static const FILE __dj_stderr_init = {
   0, 0, 0, 0,
   _IOWRT | _IONBF,
   2
 };
+
+struct ste_state {
+  FILE __dj_stderr;
+};
+
+static struct ste_state *ste;
+
+static const struct ste_state sinit =
+{
+  .__dj_stderr = __dj_stderr_init,
+};
+
+static void ste_pre(void)
+{
+#define _SV(x) ste->x = x
+  _SV(__dj_stderr);
+}
+static void ste_post(void)
+{
+#define _RS(x) x = ste->x
+  _RS(__dj_stderr);
+}
+DJ64_DEFINE_SWAPPABLE_CONTEXT2(ste_state, ste, sinit,
+    ste_pre(), ste_post());
diff --git a/src/libc/ansi/stdio/stdin.c b/src/libc/ansi/stdio/stdin.c
index cb3551a7..3b600484 100644
--- a/src/libc/ansi/stdio/stdin.c
+++ b/src/libc/ansi/stdio/stdin.c
@@ -2,9 +2,36 @@
 /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
 #include <stdio.h>
 #include <libc/file.h>
+#include <libc/djctx.h>
 
-FILE __dj_stdin = {
+FILE __dj_stdin;
+
+static const FILE __dj_stdin_init = {
   0, 0, 0, 0,
   _IOREAD | _IOLBF,
   0
 };
+
+struct ste_state {
+  FILE __dj_stdin;
+};
+
+static struct ste_state *ste;
+
+static const struct ste_state sinit =
+{
+  .__dj_stdin = __dj_stdin_init,
+};
+
+static void ste_pre(void)
+{
+#define _SV(x) ste->x = x
+  _SV(__dj_stdin);
+}
+static void ste_post(void)
+{
+#define _RS(x) x = ste->x
+  _RS(__dj_stdin);
+}
+DJ64_DEFINE_SWAPPABLE_CONTEXT2(ste_state, ste, sinit,
+    ste_pre(), ste_post());
diff --git a/src/libc/ansi/stdio/stdout.c b/src/libc/ansi/stdio/stdout.c
index 4d44d77b..118a6155 100644
--- a/src/libc/ansi/stdio/stdout.c
+++ b/src/libc/ansi/stdio/stdout.c
@@ -2,9 +2,36 @@
 /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
 #include <stdio.h>
 #include <libc/file.h>
+#include <libc/djctx.h>
 
-FILE __dj_stdout = {
+FILE __dj_stdout;
+
+static const FILE __dj_stdout_init = {
   0, 0, 0, 0,
   _IOWRT | _IOFBF,
   1
 };
+
+struct ste_state {
+  FILE __dj_stdout;
+};
+
+static struct ste_state *ste;
+
+static const struct ste_state sinit =
+{
+  .__dj_stdout = __dj_stdout_init,
+};
+
+static void ste_pre(void)
+{
+#define _SV(x) ste->x = x
+  _SV(__dj_stdout);
+}
+static void ste_post(void)
+{
+#define _RS(x) x = ste->x
+  _RS(__dj_stdout);
+}
+DJ64_DEFINE_SWAPPABLE_CONTEXT2(ste_state, ste, sinit,
+    ste_pre(), ste_post());
diff --git a/src/libc/ansi/stdio/stdprn.c b/src/libc/ansi/stdio/stdprn.c
index 2ebe5e4e..1cd52638 100644
--- a/src/libc/ansi/stdio/stdprn.c
+++ b/src/libc/ansi/stdio/stdprn.c
@@ -3,9 +3,36 @@
 /* Copyright (C) 1995 DJ Delorie, see COPYING.DJ for details */
 #include <stdio.h>
 #include <libc/file.h>
+#include <libc/djctx.h>
 
-FILE __dj_stdprn = {
+FILE __dj_stdprn;
+
+static const FILE __dj_stdprn_init = {
   0, 0, 0, 0,
   _IOWRT | _IONBF,
   4
 };
+
+struct ste_state {
+  FILE __dj_stdprn;
+};
+
+static struct ste_state *ste;
+
+static const struct ste_state sinit =
+{
+  .__dj_stdprn = __dj_stdprn_init,
+};
+
+static void ste_pre(void)
+{
+#define _SV(x) ste->x = x
+  _SV(__dj_stdprn);
+}
+static void ste_post(void)
+{
+#define _RS(x) x = ste->x
+  _RS(__dj_stdprn);
+}
+DJ64_DEFINE_SWAPPABLE_CONTEXT2(ste_state, ste, sinit,
+    ste_pre(), ste_post());