diff -r 7801ef4a4ce3 Lib/idlelib/PyShell.py
--- a/Lib/idlelib/PyShell.py	Tue Sep 03 19:43:49 2013 -0500
+++ b/Lib/idlelib/PyShell.py	Wed Sep 04 23:50:45 2013 +0300
@@ -1268,16 +1268,6 @@
         self.set_line_and_column()
 
     def write(self, s, tags=()):
-        if isinstance(s, str) and len(s) and max(s) > '\uffff':
-            # Tk doesn't support outputting non-BMP characters
-            # Let's assume what printed string is not very long,
-            # find first non-BMP character and construct informative
-            # UnicodeEncodeError exception.
-            for start, char in enumerate(s):
-                if char > '\uffff':
-                    break
-            raise UnicodeEncodeError("UCS-2", char, start, start+1,
-                                     'Non-BMP character not supported in Tk')
         try:
             self.text.mark_gravity("iomark", "right")
             count = OutputWindow.write(self, s, tags, "iomark")
diff -r 7801ef4a4ce3 Lib/test/test_tcl.py
--- a/Lib/test/test_tcl.py	Tue Sep 03 19:43:49 2013 -0500
+++ b/Lib/test/test_tcl.py	Wed Sep 04 23:50:45 2013 +0300
@@ -163,6 +163,9 @@
         self.assertEqual(passValue(False), False)
         self.assertEqual(passValue('string'), 'string')
         self.assertEqual(passValue('string\u20ac'), 'string\u20ac')
+        self.assertEqual(passValue('string\ud801'), 'string\ud801')
+        self.assertEqual(passValue('string\ud801\udca2'), 'string\ud801\udca2')
+        self.assertEqual(passValue('string\U000104a2'), 'string\U000104a2')
         for i in (0, 1, -1, 2**31-1, -2**31):
             self.assertEqual(passValue(i), i)
         for f in (0.0, 1.0, -1.0, 1/3,
diff -r 7801ef4a4ce3 Modules/_tkinter.c
--- a/Modules/_tkinter.c	Tue Sep 03 19:43:49 2013 -0500
+++ b/Modules/_tkinter.c	Wed Sep 04 23:50:45 2013 +0300
@@ -442,6 +442,19 @@
 
 
 static PyObject *
+fromTclStringAndSize(const char *s, Py_ssize_t size)
+{
+    return PyUnicode_DecodeUTF8(s, size, "replace");
+}
+
+static PyObject *
+fromTclString(const char *s)
+{
+    return fromTclStringAndSize(s, strlen(s));
+}
+
+
+static PyObject *
 Split(char *list)
 {
     int argc;
@@ -458,13 +471,13 @@
          * Could be a quoted string containing funnies, e.g. {"}.
          * Return the string itself.
          */
-        return PyUnicode_FromString(list);
+        return fromTclString(list);
     }
 
     if (argc == 0)
         v = PyUnicode_FromString("");
     else if (argc == 1)
-        v = PyUnicode_FromString(argv[0]);
+        v = fromTclString(argv[0]);
     else if ((v = PyTuple_New(argc)) != NULL) {
         int i;
         PyObject *w;
@@ -807,7 +820,7 @@
     int len;
     if (!self->string) {
         s = Tcl_GetStringFromObj(self->value, &len);
-        self->string = PyUnicode_FromStringAndSize(s, len);
+        self->string = fromTclStringAndSize(s, len);
         if (!self->string)
             return NULL;
     }
@@ -896,7 +909,7 @@
 static PyObject*
 get_typename(PyTclObject* obj, void* ignored)
 {
-    return PyUnicode_FromString(obj->value->typePtr->name);
+    return fromTclString(obj->value->typePtr->name);
 }
 
 
@@ -1008,6 +1021,27 @@
             return NULL;
         }
         kind = PyUnicode_KIND(value);
+        if (kind == sizeof(Tcl_UniChar))
+            return Tcl_NewUnicodeObj(inbuf, size);
+        if (PyUnicode_IS_COMPACT_ASCII(value) || kind > sizeof(Tcl_UniChar)) {
+            PyObject *bytes = NULL;
+            const char *utf8 = PyUnicode_AsUTF8AndSize(value, &size);
+            if (utf8 == NULL) {
+                bytes = PyUnicode_AsEncodedString(value, "utf-8", "surrogatepass");
+                if (bytes == NULL)
+                    return NULL;
+                utf8 = PyBytes_AS_STRING(bytes);
+                size = PyBytes_GET_SIZE(bytes);
+            }
+            if (size > INT_MAX) {
+                PyErr_Format(Tkinter_TclError, "string too long");
+                Py_XDECREF(bytes);
+                return NULL;
+            }
+            result = Tcl_NewStringObj(utf8, size);
+            Py_XDECREF(bytes);
+            return result;
+        }
         allocsize = ((size_t)size) * sizeof(Tcl_UniChar);
         outbuf = (Tcl_UniChar*)ckalloc(allocsize);
         /* Else overflow occurred, and we take the next exit */
@@ -1015,23 +1049,8 @@
             PyErr_NoMemory();
             return NULL;
         }
-        for (i = 0; i < size; i++) {
-            Py_UCS4 ch = PyUnicode_READ(kind, inbuf, i);
-            /* We cannot test for sizeof(Tcl_UniChar) directly,
-               so we test for UTF-8 size instead. */
-#if TCL_UTF_MAX == 3
-            if (ch >= 0x10000) {
-                /* Tcl doesn't do UTF-16, yet. */
-                PyErr_Format(Tkinter_TclError,
-                             "character U+%x is above the range "
-                             "(U+0000-U+FFFF) allowed by Tcl",
-                             ch);
-                ckfree(FREECAST outbuf);
-                return NULL;
-            }
-#endif
-            outbuf[i] = ch;
-        }
+        for (i = 0; i < size; i++)
+            outbuf[i] = (Tcl_UniChar)PyUnicode_READ(kind, inbuf, i);
         result = Tcl_NewUnicodeObj(outbuf, size);
         ckfree(FREECAST outbuf);
         return result;
@@ -1058,8 +1077,7 @@
     TkappObject *app = (TkappObject*)tkapp;
 
     if (value->typePtr == NULL) {
-        return PyUnicode_FromStringAndSize(value->bytes,
-                                           value->length);
+        return fromTclStringAndSize(value->bytes, value->length);
     }
 
     if (value->typePtr == app->BooleanType) {
@@ -1116,15 +1134,9 @@
     }
 
     if (value->typePtr == app->StringType) {
-#if TCL_UTF_MAX==3
         return PyUnicode_FromKindAndData(
-            PyUnicode_2BYTE_KIND, Tcl_GetUnicode(value),
+            sizeof(Tcl_UniChar), Tcl_GetUnicode(value),
             Tcl_GetCharLength(value));
-#else
-        return PyUnicode_FromKindAndData(
-            PyUnicode_4BYTE_KIND, Tcl_GetUnicode(value),
-            Tcl_GetCharLength(value));
-#endif
     }
 
     return newPyTclObject(value);
@@ -1230,7 +1242,7 @@
         const char *s = Tcl_GetStringResult(self->interp);
         const char *p = s;
 
-        res = PyUnicode_FromStringAndSize(s, (int)(p-s));
+        res = fromTclStringAndSize(s, (int)(p-s));
     }
     return res;
 }
@@ -1421,7 +1433,7 @@
     if (err == TCL_ERROR)
         res = Tkinter_Error(self);
     else
-        res = PyUnicode_FromString(Tkapp_Result(self));
+        res = fromTclString(Tkapp_Result(self));
     LEAVE_OVERLAP_TCL
     return res;
 }
@@ -1473,7 +1485,7 @@
         res = Tkinter_Error(self);
 
     else
-        res = PyUnicode_FromString(Tkapp_Result(self));
+        res = fromTclString(Tkapp_Result(self));
     LEAVE_OVERLAP_TCL
     return res;
 }
@@ -1496,7 +1508,7 @@
     if (err == TCL_ERROR)
         res = Tkinter_Error(self);
     else
-        res = PyUnicode_FromString(Tkapp_Result(self));
+        res = fromTclString(Tkapp_Result(self));
     LEAVE_OVERLAP_TCL
     return res;
 }
@@ -1719,7 +1731,7 @@
             res = FromObj(self, tres);
         }
         else {
-            res = PyUnicode_FromString(Tcl_GetString(tres));
+            res = fromTclString(Tcl_GetString(tres));
         }
     }
     LEAVE_OVERLAP_TCL
@@ -1982,7 +1994,7 @@
         goto finally;
 
     for (i = 0; i < argc; i++) {
-        PyObject *s = PyUnicode_FromString(argv[i]);
+        PyObject *s = fromTclString(argv[i]);
         if (!s || PyTuple_SetItem(v, i, s)) {
             Py_DECREF(v);
             v = NULL;
@@ -2101,7 +2113,7 @@
         return PythonCmd_Error(interp);
 
     for (i = 0; i < (argc - 1); i++) {
-        PyObject *s = PyUnicode_FromString(argv[i + 1]);
+        PyObject *s = fromTclString(argv[i + 1]);
         if (!s) {
             /* Is Tk leaking 0xC080 in %A - a "modified" utf-8 null? */
             if (PyErr_ExceptionMatches(PyExc_UnicodeDecodeError) &&