diff --git a/extmod/misc.h b/extmod/misc.h
new file mode 100644
index 0000000000..032fcba613
--- /dev/null
+++ b/extmod/misc.h
@@ -0,0 +1,32 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2014-2016 Damien P. George
+ * Copyright (c) 2016 Paul Sokolovsky
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+// This file contains cumulative declarations for extmod/ .
+
+#include "py/runtime.h"
+
+MP_DECLARE_CONST_FUN_OBJ(mp_uos_dupterm_obj);
diff --git a/extmod/moduos_dupterm.c b/extmod/moduos_dupterm.c
new file mode 100644
index 0000000000..d20986279a
--- /dev/null
+++ b/extmod/moduos_dupterm.c
@@ -0,0 +1,55 @@
+/*
+ * This file is part of the MicroPython project, http://micropython.org/
+ *
+ * The MIT License (MIT)
+ *
+ * Copyright (c) 2016 Paul Sokolovsky
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include <errno.h>
+#include <string.h>
+#include "py/mpconfig.h"
+
+#include "py/nlr.h"
+#include "py/runtime.h"
+#include "py/objtuple.h"
+
+#if MICROPY_PY_OS_DUPTERM
+
+STATIC mp_obj_t mp_uos_dupterm(mp_uint_t n_args, const mp_obj_t *args) {
+    if (n_args == 0) {
+        if (MP_STATE_PORT(term_obj) == MP_OBJ_NULL) {
+            return mp_const_none;
+        } else {
+            return MP_STATE_PORT(term_obj);
+        }
+    } else {
+        if (args[0] == mp_const_none) {
+            MP_STATE_PORT(term_obj) = NULL;
+        } else {
+            MP_STATE_PORT(term_obj) = args[0];
+        }
+        return mp_const_none;
+    }
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_uos_dupterm_obj, 0, 1, mp_uos_dupterm);
+
+#endif
diff --git a/py/py.mk b/py/py.mk
index f988193f02..4574ec9a68 100644
--- a/py/py.mk
+++ b/py/py.mk
@@ -169,6 +169,7 @@ PY_O_BASENAME = \
 	../extmod/machine_mem.o \
 	../extmod/modussl.o \
 	../extmod/fsusermount.o \
+	../extmod/moduos_dupterm.o \
 
 # prepend the build destination prefix to the py object files
 PY_O = $(addprefix $(PY_BUILD)/, $(PY_O_BASENAME))
diff --git a/unix/modos.c b/unix/modos.c
index f2e83a1643..ee61ad3f38 100644
--- a/unix/modos.c
+++ b/unix/modos.c
@@ -37,6 +37,7 @@
 #include "py/nlr.h"
 #include "py/runtime.h"
 #include "py/objtuple.h"
+#include "extmod/misc.h"
 
 #ifdef __ANDROID__
 #define USE_STATFS 1
@@ -215,26 +216,6 @@ STATIC mp_obj_t mod_os_errno(mp_uint_t n_args, const mp_obj_t *args) {
 }
 STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_os_errno_obj, 0, 1, mod_os_errno);
 
-#if MICROPY_PY_OS_DUPTERM
-STATIC mp_obj_t mod_os_dupterm(mp_uint_t n_args, const mp_obj_t *args) {
-    if (n_args == 0) {
-        if (MP_STATE_PORT(term_obj) == MP_OBJ_NULL) {
-            return mp_const_none;
-        } else {
-            return MP_STATE_PORT(term_obj);
-        }
-    } else {
-        if (args[0] == mp_const_none) {
-            MP_STATE_PORT(term_obj) = NULL;
-        } else {
-            MP_STATE_PORT(term_obj) = args[0];
-        }
-        return mp_const_none;
-    }
-}
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mod_os_dupterm_obj, 0, 1, mod_os_dupterm);
-#endif
-
 STATIC const mp_rom_map_elem_t mp_module_os_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR___name__), MP_ROM_QSTR(MP_QSTR_uos) },
     { MP_ROM_QSTR(MP_QSTR_errno), MP_ROM_PTR(&mod_os_errno_obj) },
@@ -248,7 +229,7 @@ STATIC const mp_rom_map_elem_t mp_module_os_globals_table[] = {
     { MP_ROM_QSTR(MP_QSTR_mkdir), MP_ROM_PTR(&mod_os_mkdir_obj) },
     { MP_ROM_QSTR(MP_QSTR_ilistdir), MP_ROM_PTR(&mod_os_ilistdir_obj) },
     #if MICROPY_PY_OS_DUPTERM
-    { MP_ROM_QSTR(MP_QSTR_dupterm), MP_ROM_PTR(&mod_os_dupterm_obj) },
+    { MP_ROM_QSTR(MP_QSTR_dupterm), MP_ROM_PTR(&mp_uos_dupterm_obj) },
     #endif
 };