diff --git a/Lib/lib-tk/Tkinter.py b/Lib/lib-tk/Tkinter.py
index 8d21717b467..cb7edf0ed44 100644
--- a/Lib/lib-tk/Tkinter.py
+++ b/Lib/lib-tk/Tkinter.py
@@ -401,6 +401,10 @@ class BooleanVar(Variable):
         """
         Variable.__init__(self, master, value, name)
 
+    def set(self, value):
+        """Set the variable to VALUE."""
+        return self._tk.globalsetvar(self._name, self._tk.getboolean(value))
+
     def get(self):
         """Return the value of the variable as a bool."""
         return self._tk.getboolean(self._tk.globalgetvar(self._name))
diff --git a/Lib/lib-tk/test/test_tkinter/test_variables.py b/Lib/lib-tk/test/test_tkinter/test_variables.py
index c11d8cdf990..5e07528c6d8 100644
--- a/Lib/lib-tk/test/test_tkinter/test_variables.py
+++ b/Lib/lib-tk/test/test_tkinter/test_variables.py
@@ -1,6 +1,7 @@
 import unittest
 
-from Tkinter import Variable, StringVar, IntVar, DoubleVar, BooleanVar, Tcl, TclError
+from Tkinter import (Variable, StringVar, IntVar, DoubleVar, BooleanVar, Tcl,
+                     TclError)
 
 
 class TestBase(unittest.TestCase):
@@ -139,16 +140,57 @@ class TestBooleanVar(TestBase):
 
     def test_default(self):
         v = BooleanVar(self.root)
-        self.assertEqual(False, v.get())
+        self.assertIs(v.get(), False)
 
     def test_get(self):
         v = BooleanVar(self.root, True, "name")
-        self.assertAlmostEqual(True, v.get())
+        self.assertIs(v.get(), True)
         self.root.globalsetvar("name", "0")
-        self.assertAlmostEqual(False, v.get())
+        self.assertIs(v.get(), False)
+        self.root.globalsetvar("name", 42 if self.root.wantobjects() else 1)
+        self.assertIs(v.get(), True)
+        self.root.globalsetvar("name", 0)
+        self.assertIs(v.get(), False)
+        self.root.globalsetvar("name", 42L if self.root.wantobjects() else 1L)
+        self.assertIs(v.get(), True)
+        self.root.globalsetvar("name", 0L)
+        self.assertIs(v.get(), False)
+        self.root.globalsetvar("name", "on")
+        self.assertIs(v.get(), True)
+        self.root.globalsetvar("name", u"0")
+        self.assertIs(v.get(), False)
+        self.root.globalsetvar("name", u"on")
+        self.assertIs(v.get(), True)
+
+    def test_set(self):
+        true = 1 if self.root.wantobjects() else "1"
+        false = 0 if self.root.wantobjects() else "0"
+        v = BooleanVar(self.root, name="name")
+        v.set(True)
+        self.assertEqual(self.root.globalgetvar("name"), true)
+        v.set("0")
+        self.assertEqual(self.root.globalgetvar("name"), false)
+        v.set(42)
+        self.assertEqual(self.root.globalgetvar("name"), true)
+        v.set(0)
+        self.assertEqual(self.root.globalgetvar("name"), false)
+        v.set(42L)
+        self.assertEqual(self.root.globalgetvar("name"), true)
+        v.set(0L)
+        self.assertEqual(self.root.globalgetvar("name"), false)
+        v.set("on")
+        self.assertEqual(self.root.globalgetvar("name"), true)
+        v.set(u"0")
+        self.assertEqual(self.root.globalgetvar("name"), false)
+        v.set(u"on")
+        self.assertEqual(self.root.globalgetvar("name"), true)
 
     def test_invalid_value_domain(self):
+        false = 0 if self.root.wantobjects() else "0"
         v = BooleanVar(self.root, name="name")
+        with self.assertRaises(TclError):
+            v.set("value")
+        self.assertEqual(self.root.globalgetvar("name"), false)
         self.root.globalsetvar("name", "value")
         with self.assertRaises(TclError):
             v.get()
diff --git a/Lib/lib-tk/ttk.py b/Lib/lib-tk/ttk.py
index 58f769895dd..08cb040bd95 100644
--- a/Lib/lib-tk/ttk.py
+++ b/Lib/lib-tk/ttk.py
@@ -575,7 +575,7 @@ class Widget(Tkinter.Widget):
         if ret and callback:
             return callback(*args, **kw)
 
-        return bool(ret)
+        return ret
 
 
     def state(self, statespec=None):
@@ -683,7 +683,7 @@ class Entry(Widget, Tkinter.Entry):
         """Force revalidation, independent of the conditions specified
         by the validate option. Returns False if validation fails, True
         if it succeeds. Sets or clears the invalid state accordingly."""
-        return bool(self.tk.getboolean(self.tk.call(self._w, "validate")))
+        return self.tk.getboolean(self.tk.call(self._w, "validate"))
 
 
 class Combobox(Entry):
@@ -1233,7 +1233,7 @@ class Treeview(Widget, Tkinter.XView, Tkinter.YView):
     def exists(self, item):
         """Returns True if the specified item is present in the tree,
         False otherwise."""
-        return bool(self.tk.getboolean(self.tk.call(self._w, "exists", item)))
+        return self.tk.getboolean(self.tk.call(self._w, "exists", item))
 
 
     def focus(self, item=None):
diff --git a/Lib/test/test_tcl.py b/Lib/test/test_tcl.py
index ff1568b6071..4167588e627 100644
--- a/Lib/test/test_tcl.py
+++ b/Lib/test/test_tcl.py
@@ -182,7 +182,12 @@ class TclTest(unittest.TestCase):
         tcl = self.interp.tk
         self.assertIs(tcl.getboolean('on'), True)
         self.assertIs(tcl.getboolean('1'), True)
-        self.assertEqual(tcl.getboolean(42), 42)
+        self.assertIs(tcl.getboolean(u'on'), True)
+        self.assertIs(tcl.getboolean(u'1'), True)
+        self.assertIs(tcl.getboolean(42), True)
+        self.assertIs(tcl.getboolean(0), False)
+        self.assertIs(tcl.getboolean(42L), True)
+        self.assertIs(tcl.getboolean(0L), False)
         self.assertRaises(TypeError, tcl.getboolean)
         self.assertRaises(TypeError, tcl.getboolean, 'on', '1')
         self.assertRaises(TypeError, tcl.getboolean, 1.0)
diff --git a/Misc/NEWS b/Misc/NEWS
index 783bf8821c0..c9febc7b5ec 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -21,6 +21,11 @@ Core and Builtins
 Library
 -------
 
+- Issue #15133: _tkinter.tkapp.getboolean() now supports long and Tcl_Obj and
+  always returns bool.  tkinter.BooleanVar now validates input values (accepted
+  bool, int, long, str, unicode, and Tcl_Obj).  tkinter.BooleanVar.get() now
+  always returns bool.
+
 - Issue #23338: Fixed formatting ctypes error messages on Cygwin.
   Patch by Makoto Kato.
 
diff --git a/Modules/_tkinter.c b/Modules/_tkinter.c
index 840b9dbdab3..bef5c0bbe8f 100644
--- a/Modules/_tkinter.c
+++ b/Modules/_tkinter.c
@@ -2163,19 +2163,26 @@ Tkapp_GetDouble(PyObject *self, PyObject *args)
 }
 
 static PyObject *
-Tkapp_GetBoolean(PyObject *self, PyObject *args)
+Tkapp_GetBoolean(PyObject *self, PyObject *arg)
 {
     char *s;
     int v;
 
-    if (PyTuple_Size(args) == 1) {
-        PyObject *o = PyTuple_GetItem(args, 0);
-        if (PyInt_Check(o)) {
-            Py_INCREF(o);
-            return o;
-        }
+    if (PyInt_Check(arg)) /* int or bool */
+        return PyBool_FromLong(PyInt_AS_LONG(arg));
+
+    if (PyLong_Check(arg))
+        return PyBool_FromLong(Py_SIZE(arg) != 0);
+
+    if (PyTclObject_Check(arg)) {
+        if (Tcl_GetBooleanFromObj(Tkapp_Interp(self),
+                                  ((PyTclObject*)arg)->value,
+                                  &v) == TCL_ERROR)
+            return Tkinter_Error(self);
+        return PyBool_FromLong(v);
     }
-    if (!PyArg_ParseTuple(args, "s:getboolean", &s))
+
+    if (!PyArg_Parse(arg, "s:getboolean", &s))
         return NULL;
     CHECK_STRING_LENGTH(s);
     if (Tcl_GetBoolean(Tkapp_Interp(self), s, &v) == TCL_ERROR)
@@ -3236,7 +3243,7 @@ static PyMethodDef Tkapp_methods[] =
     {"globalunsetvar",     Tkapp_GlobalUnsetVar, METH_VARARGS},
     {"getint",                 Tkapp_GetInt, METH_VARARGS},
     {"getdouble",              Tkapp_GetDouble, METH_VARARGS},
-    {"getboolean",             Tkapp_GetBoolean, METH_VARARGS},
+    {"getboolean",             Tkapp_GetBoolean, METH_O},
     {"exprstring",             Tkapp_ExprString, METH_VARARGS},
     {"exprlong",               Tkapp_ExprLong, METH_VARARGS},
     {"exprdouble",             Tkapp_ExprDouble, METH_VARARGS},