diff --git a/extmod/misc.h b/extmod/misc.h
index 6c13592c75..d6f6d859c6 100644
--- a/extmod/misc.h
+++ b/extmod/misc.h
@@ -35,8 +35,9 @@
 MP_DECLARE_CONST_FUN_OBJ_VAR_BETWEEN(mp_uos_dupterm_obj);
 
 #if MICROPY_PY_OS_DUPTERM
+int mp_uos_dupterm_rx_chr(void);
 void mp_uos_dupterm_tx_strn(const char *str, size_t len);
-void mp_uos_deactivate(const char *msg, mp_obj_t exc);
+void mp_uos_deactivate(size_t dupterm_idx, const char *msg, mp_obj_t exc);
 #else
 #define mp_uos_dupterm_tx_strn(s, l)
 #endif
diff --git a/extmod/uos_dupterm.c b/extmod/uos_dupterm.c
index 1d6f02dcea..d4326d3265 100644
--- a/extmod/uos_dupterm.c
+++ b/extmod/uos_dupterm.c
@@ -4,6 +4,7 @@
  * The MIT License (MIT)
  *
  * Copyright (c) 2016 Paul Sokolovsky
+ * Copyright (c) 2017 Damien P. George
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
@@ -31,12 +32,13 @@
 #include "py/objtuple.h"
 #include "py/objarray.h"
 #include "py/stream.h"
+#include "lib/utils/interrupt_char.h"
 
 #if MICROPY_PY_OS_DUPTERM
 
-void mp_uos_deactivate(const char *msg, mp_obj_t exc) {
-    mp_obj_t term = MP_STATE_PORT(term_obj);
-    MP_STATE_PORT(term_obj) = NULL;
+void mp_uos_deactivate(size_t dupterm_idx, const char *msg, mp_obj_t exc) {
+    mp_obj_t term = MP_STATE_VM(dupterm_objs[dupterm_idx]);
+    MP_STATE_VM(dupterm_objs[dupterm_idx]) = MP_OBJ_NULL;
     mp_printf(&mp_plat_print, msg);
     if (exc != MP_OBJ_NULL) {
         mp_obj_print_exception(&mp_plat_print, exc);
@@ -44,48 +46,94 @@ void mp_uos_deactivate(const char *msg, mp_obj_t exc) {
     mp_stream_close(term);
 }
 
+int mp_uos_dupterm_rx_chr(void) {
+    for (size_t idx = 0; idx < MICROPY_PY_OS_DUPTERM; ++idx) {
+        if (MP_STATE_VM(dupterm_objs[idx]) == MP_OBJ_NULL) {
+            continue;
+        }
+
+        nlr_buf_t nlr;
+        if (nlr_push(&nlr) == 0) {
+            mp_obj_t readinto_m[3];
+            mp_load_method(MP_STATE_VM(dupterm_objs[idx]), MP_QSTR_readinto, readinto_m);
+            readinto_m[2] = MP_STATE_VM(dupterm_arr_obj);
+            mp_obj_t res = mp_call_method_n_kw(1, 0, readinto_m);
+            if (res == mp_const_none) {
+                nlr_pop();
+            } else if (res == MP_OBJ_NEW_SMALL_INT(0)) {
+                mp_uos_deactivate(idx, "dupterm: EOF received, deactivating\n", MP_OBJ_NULL);
+                nlr_pop();
+            } else {
+                mp_buffer_info_t bufinfo;
+                mp_get_buffer_raise(MP_STATE_VM(dupterm_arr_obj), &bufinfo, MP_BUFFER_READ);
+                nlr_pop();
+                if (*(byte*)bufinfo.buf == mp_interrupt_char) {
+                    // Signal keyboard interrupt to be raised as soon as the VM resumes
+                    mp_keyboard_interrupt();
+                    return -2;
+                }
+                return *(byte*)bufinfo.buf;
+            }
+        } else {
+            mp_uos_deactivate(idx, "dupterm: Exception in read() method, deactivating: ", nlr.ret_val);
+        }
+    }
+
+    // No chars available
+    return -1;
+}
+
 void mp_uos_dupterm_tx_strn(const char *str, size_t len) {
-    if (MP_STATE_PORT(term_obj) != MP_OBJ_NULL) {
+    for (size_t idx = 0; idx < MICROPY_PY_OS_DUPTERM; ++idx) {
+        if (MP_STATE_VM(dupterm_objs[idx]) == MP_OBJ_NULL) {
+            continue;
+        }
         nlr_buf_t nlr;
         if (nlr_push(&nlr) == 0) {
             mp_obj_t write_m[3];
-            mp_load_method(MP_STATE_PORT(term_obj), MP_QSTR_write, write_m);
+            mp_load_method(MP_STATE_VM(dupterm_objs[idx]), MP_QSTR_write, write_m);
 
-            mp_obj_array_t *arr = MP_OBJ_TO_PTR(MP_STATE_PORT(dupterm_arr_obj));
+            mp_obj_array_t *arr = MP_OBJ_TO_PTR(MP_STATE_VM(dupterm_arr_obj));
             void *org_items = arr->items;
             arr->items = (void*)str;
             arr->len = len;
-            write_m[2] = MP_STATE_PORT(dupterm_arr_obj);
+            write_m[2] = MP_STATE_VM(dupterm_arr_obj);
             mp_call_method_n_kw(1, 0, write_m);
-            arr = MP_OBJ_TO_PTR(MP_STATE_PORT(dupterm_arr_obj));
+            arr = MP_OBJ_TO_PTR(MP_STATE_VM(dupterm_arr_obj));
             arr->items = org_items;
             arr->len = 1;
             nlr_pop();
         } else {
-            mp_uos_deactivate("dupterm: Exception in write() method, deactivating: ", nlr.ret_val);
+            mp_uos_deactivate(idx, "dupterm: Exception in write() method, deactivating: ", nlr.ret_val);
         }
     }
 }
 
 STATIC mp_obj_t mp_uos_dupterm(size_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) = MP_OBJ_NULL;
-        } else {
-            MP_STATE_PORT(term_obj) = args[0];
-            if (MP_STATE_PORT(dupterm_arr_obj) == MP_OBJ_NULL) {
-                MP_STATE_PORT(dupterm_arr_obj) = mp_obj_new_bytearray(1, "");
-            }
-        }
-        return mp_const_none;
+    mp_int_t idx = 0;
+    if (n_args == 2) {
+        idx = mp_obj_get_int(args[1]);
     }
+
+    if (idx < 0 || idx >= MICROPY_PY_OS_DUPTERM) {
+        mp_raise_ValueError("invalid dupterm index");
+    }
+
+    mp_obj_t previous_obj = MP_STATE_VM(dupterm_objs[idx]);
+    if (previous_obj == MP_OBJ_NULL) {
+        previous_obj = mp_const_none;
+    }
+    if (args[0] == mp_const_none) {
+        MP_STATE_VM(dupterm_objs[idx]) = MP_OBJ_NULL;
+    } else {
+        MP_STATE_VM(dupterm_objs[idx]) = args[0];
+        if (MP_STATE_VM(dupterm_arr_obj) == MP_OBJ_NULL) {
+            MP_STATE_VM(dupterm_arr_obj) = mp_obj_new_bytearray(1, "");
+        }
+    }
+
+    return previous_obj;
 }
-MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_uos_dupterm_obj, 0, 1, mp_uos_dupterm);
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_uos_dupterm_obj, 1, 2, mp_uos_dupterm);
 
 #endif
diff --git a/ports/esp8266/esp_mphal.c b/ports/esp8266/esp_mphal.c
index 71d4c50628..9f4f051fdd 100644
--- a/ports/esp8266/esp_mphal.c
+++ b/ports/esp8266/esp_mphal.c
@@ -155,41 +155,6 @@ void mp_hal_signal_input(void) {
     #endif
 }
 
-static int call_dupterm_read(void) {
-    if (MP_STATE_PORT(term_obj) == NULL) {
-        return -1;
-    }
-
-    nlr_buf_t nlr;
-    if (nlr_push(&nlr) == 0) {
-        mp_obj_t readinto_m[3];
-        mp_load_method(MP_STATE_PORT(term_obj), MP_QSTR_readinto, readinto_m);
-        readinto_m[2] = MP_STATE_PORT(dupterm_arr_obj);
-        mp_obj_t res = mp_call_method_n_kw(1, 0, readinto_m);
-        if (res == mp_const_none) {
-            nlr_pop();
-            return -2;
-        }
-        if (res == MP_OBJ_NEW_SMALL_INT(0)) {
-            mp_uos_deactivate("dupterm: EOF received, deactivating\n", MP_OBJ_NULL);
-            nlr_pop();
-            return -1;
-        }
-        mp_buffer_info_t bufinfo;
-        mp_get_buffer_raise(MP_STATE_PORT(dupterm_arr_obj), &bufinfo, MP_BUFFER_READ);
-        nlr_pop();
-        if (*(byte*)bufinfo.buf == mp_interrupt_char) {
-            mp_keyboard_interrupt();
-            return -2;
-        }
-        return *(byte*)bufinfo.buf;
-    } else {
-        mp_uos_deactivate("dupterm: Exception in read() method, deactivating: ", nlr.ret_val);
-    }
-
-    return -1;
-}
-
 STATIC void dupterm_task_handler(os_event_t *evt) {
     static byte lock;
     if (lock) {
@@ -197,7 +162,7 @@ STATIC void dupterm_task_handler(os_event_t *evt) {
     }
     lock = 1;
     while (1) {
-        int c = call_dupterm_read();
+        int c = mp_uos_dupterm_rx_chr();
         if (c < 0) {
             break;
         }
diff --git a/ports/esp8266/main.c b/ports/esp8266/main.c
index 7f5dca84e2..d1b88a8cec 100644
--- a/ports/esp8266/main.c
+++ b/ports/esp8266/main.c
@@ -51,8 +51,6 @@ STATIC void mp_reset(void) {
     mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_lib));
     mp_obj_list_append(mp_sys_path, MP_OBJ_NEW_QSTR(MP_QSTR__slash_));
     mp_obj_list_init(mp_sys_argv, 0);
-    MP_STATE_PORT(term_obj) = MP_OBJ_NULL;
-    MP_STATE_PORT(dupterm_arr_obj) = MP_OBJ_NULL;
     #if MICROPY_EMIT_XTENSA || MICROPY_EMIT_INLINE_XTENSA
     extern void esp_native_code_init(void);
     esp_native_code_init();
diff --git a/ports/esp8266/modules/webrepl.py b/ports/esp8266/modules/webrepl.py
index 5a76e9b26d..aa156d1487 100644
--- a/ports/esp8266/modules/webrepl.py
+++ b/ports/esp8266/modules/webrepl.py
@@ -31,7 +31,9 @@ def setup_conn(port, accept_handler):
 def accept_conn(listen_sock):
     global client_s
     cl, remote_addr = listen_sock.accept()
-    if uos.dupterm():
+    prev = uos.dupterm(None)
+    uos.dupterm(prev)
+    if prev:
         print("\nConcurrent WebREPL connection from", remote_addr, "rejected")
         cl.close()
         return
diff --git a/ports/unix/unix_mphal.c b/ports/unix/unix_mphal.c
index 2b273d8341..f27c62fd1d 100644
--- a/ports/unix/unix_mphal.c
+++ b/ports/unix/unix_mphal.c
@@ -108,11 +108,11 @@ void mp_hal_stdio_mode_orig(void) {
 #endif
 
 #if MICROPY_PY_OS_DUPTERM
-static int call_dupterm_read(void) {
+static int call_dupterm_read(size_t idx) {
     nlr_buf_t nlr;
     if (nlr_push(&nlr) == 0) {
         mp_obj_t read_m[3];
-        mp_load_method(MP_STATE_PORT(term_obj), MP_QSTR_read, read_m);
+        mp_load_method(MP_STATE_VM(dupterm_objs[idx]), MP_QSTR_read, read_m);
         read_m[2] = MP_OBJ_NEW_SMALL_INT(1);
         mp_obj_t res = mp_call_method_n_kw(1, 0, read_m);
         if (res == mp_const_none) {
@@ -122,18 +122,18 @@ static int call_dupterm_read(void) {
         mp_get_buffer_raise(res, &bufinfo, MP_BUFFER_READ);
         if (bufinfo.len == 0) {
             mp_printf(&mp_plat_print, "dupterm: EOF received, deactivating\n");
-            MP_STATE_PORT(term_obj) = NULL;
+            MP_STATE_VM(dupterm_objs[idx]) = MP_OBJ_NULL;
             return -1;
         }
         nlr_pop();
         return *(byte*)bufinfo.buf;
     } else {
         // Temporarily disable dupterm to avoid infinite recursion
-        mp_obj_t save_term = MP_STATE_PORT(term_obj);
-        MP_STATE_PORT(term_obj) = NULL;
+        mp_obj_t save_term = MP_STATE_VM(dupterm_objs[idx]);
+        MP_STATE_VM(dupterm_objs[idx]) = NULL;
         mp_printf(&mp_plat_print, "dupterm: ");
         mp_obj_print_exception(&mp_plat_print, nlr.ret_val);
-        MP_STATE_PORT(term_obj) = save_term;
+        MP_STATE_VM(dupterm_objs[idx]) = save_term;
     }
 
     return -1;
@@ -143,10 +143,11 @@ static int call_dupterm_read(void) {
 int mp_hal_stdin_rx_chr(void) {
     unsigned char c;
 #if MICROPY_PY_OS_DUPTERM
-    if (MP_STATE_PORT(term_obj) != MP_OBJ_NULL) {
+    // TODO only support dupterm one slot at the moment
+    if (MP_STATE_VM(dupterm_objs[0]) != MP_OBJ_NULL) {
         int c;
         do {
-             c = call_dupterm_read();
+             c = call_dupterm_read(0);
         } while (c == -2);
         if (c == -1) {
             goto main_term;
diff --git a/py/mpstate.h b/py/mpstate.h
index eca14a9e44..6a39ebdea9 100644
--- a/py/mpstate.h
+++ b/py/mpstate.h
@@ -168,7 +168,7 @@ typedef struct _mp_state_vm_t {
     // root pointers for extmod
 
     #if MICROPY_PY_OS_DUPTERM
-    mp_obj_t term_obj;
+    mp_obj_t dupterm_objs[MICROPY_PY_OS_DUPTERM];
     mp_obj_t dupterm_arr_obj;
     #endif
 
diff --git a/py/runtime.c b/py/runtime.c
index 069548debb..17e5d235c9 100644
--- a/py/runtime.c
+++ b/py/runtime.c
@@ -102,6 +102,13 @@ void mp_init(void) {
     MP_STATE_VM(mp_module_builtins_override_dict) = NULL;
     #endif
 
+    #if MICROPY_PY_OS_DUPTERM
+    for (size_t i = 0; i < MICROPY_PY_OS_DUPTERM; ++i) {
+        MP_STATE_VM(dupterm_objs[i]) = MP_OBJ_NULL;
+    }
+    MP_STATE_VM(dupterm_arr_obj) = MP_OBJ_NULL;
+    #endif
+
     #if MICROPY_FSUSERMOUNT
     // zero out the pointers to the user-mounted devices
     memset(MP_STATE_VM(fs_user_mount), 0, sizeof(MP_STATE_VM(fs_user_mount)));