4 files changed, 86 insertions, 2 deletions

diff --git a/Lib/test/test_clinic.py b/Lib/test/test_clinic.py
index 199050d0d61..0c99620e27c 100644
--- a/Lib/test/test_clinic.py
+++ b/Lib/test/test_clinic.py
@@ -3032,6 +3032,11 @@ class ClinicFunctionalTest(unittest.TestCase):
         self.assertEqual(ac_tester.bool_converter('', [], 5), (False, False, True))
         self.assertEqual(ac_tester.bool_converter(('not empty',), {1: 2}, 0), (True, True, False))
 
+    def test_bool_converter_c_default(self):
+        self.assertEqual(ac_tester.bool_converter_c_default(), (1, 0, -2, -3))
+        self.assertEqual(ac_tester.bool_converter_c_default(False, True, False, True),
+                         (0, 1, 0, 1))
+
     def test_char_converter(self):
         with self.assertRaises(TypeError):
             ac_tester.char_converter(1)
diff --git a/Modules/_testclinic.c b/Modules/_testclinic.c
index 0a1f13db6ca..3e903b6d87d 100644
--- a/Modules/_testclinic.c
+++ b/Modules/_testclinic.c
@@ -225,6 +225,25 @@ bool_converter_impl(PyObject *module, int a, int b, int c)
 
 
 /*[clinic input]
+bool_converter_c_default
+
+    a: bool = True
+    b: bool = False
+    c: bool(c_default="-2") = True
+    d: bool(c_default="-3") = x
+    /
+
+[clinic start generated code]*/
+
+static PyObject *
+bool_converter_c_default_impl(PyObject *module, int a, int b, int c, int d)
+/*[clinic end generated code: output=cf204382e1e4c30c input=185786302ab84081]*/
+{
+    return Py_BuildValue("iiii", a, b, c, d);
+}
+
+
+/*[clinic input]
 char_converter
 
     a: char = b'A'
@@ -2296,6 +2315,7 @@ static PyMethodDef tester_methods[] = {
     BYTE_ARRAY_OBJECT_CONVERTER_METHODDEF
     UNICODE_CONVERTER_METHODDEF
     BOOL_CONVERTER_METHODDEF
+    BOOL_CONVERTER_C_DEFAULT_METHODDEF
     CHAR_CONVERTER_METHODDEF
     UNSIGNED_CHAR_CONVERTER_METHODDEF
     SHORT_CONVERTER_METHODDEF
diff --git a/Modules/clinic/_testclinic.c.h b/Modules/clinic/_testclinic.c.h
index 56b0ca316d4..636eea665e9 100644
--- a/Modules/clinic/_testclinic.c.h
+++ b/Modules/clinic/_testclinic.c.h
@@ -195,6 +195,64 @@ exit:
     return return_value;
 }
 
+PyDoc_STRVAR(bool_converter_c_default__doc__,
+"bool_converter_c_default($module, a=True, b=False, c=True, d=x, /)\n"
+"--\n"
+"\n");
+
+#define BOOL_CONVERTER_C_DEFAULT_METHODDEF    \
+    {"bool_converter_c_default", _PyCFunction_CAST(bool_converter_c_default), METH_FASTCALL, bool_converter_c_default__doc__},
+
+static PyObject *
+bool_converter_c_default_impl(PyObject *module, int a, int b, int c, int d);
+
+static PyObject *
+bool_converter_c_default(PyObject *module, PyObject *const *args, Py_ssize_t nargs)
+{
+    PyObject *return_value = NULL;
+    int a = 1;
+    int b = 0;
+    int c = -2;
+    int d = -3;
+
+    if (!_PyArg_CheckPositional("bool_converter_c_default", nargs, 0, 4)) {
+        goto exit;
+    }
+    if (nargs < 1) {
+        goto skip_optional;
+    }
+    a = PyObject_IsTrue(args[0]);
+    if (a < 0) {
+        goto exit;
+    }
+    if (nargs < 2) {
+        goto skip_optional;
+    }
+    b = PyObject_IsTrue(args[1]);
+    if (b < 0) {
+        goto exit;
+    }
+    if (nargs < 3) {
+        goto skip_optional;
+    }
+    c = PyObject_IsTrue(args[2]);
+    if (c < 0) {
+        goto exit;
+    }
+    if (nargs < 4) {
+        goto skip_optional;
+    }
+    d = PyObject_IsTrue(args[3]);
+    if (d < 0) {
+        goto exit;
+    }
+skip_optional:
+    return_value = bool_converter_c_default_impl(module, a, b, c, d);
+
+exit:
+    return return_value;
+}
+
 PyDoc_STRVAR(char_converter__doc__,
 "char_converter($module, a=b\'A\', b=b\'\\x07\', c=b\'\\x08\', d=b\'\\t\', e=b\'\\n\',\n"
 "               f=b\'\\x0b\', g=b\'\\x0c\', h=b\'\\r\', i=b\'\"\', j=b\"\'\", k=b\'?\',\n"
@@ -4423,4 +4481,4 @@ _testclinic_TestClass_posonly_poskw_varpos_array_no_fastcall(PyObject *type, PyO
 exit:
     return return_value;
 }
-/*[clinic end generated code: output=ea0b8fb0949fa49f input=a9049054013a1b77]*/
+/*[clinic end generated code: output=b57b94aeba0882b4 input=a9049054013a1b77]*/
diff --git a/Tools/clinic/libclinic/converters.py b/Tools/clinic/libclinic/converters.py
index 871d7542ba0..b176ee4ecd4 100644
--- a/Tools/clinic/libclinic/converters.py
+++ b/Tools/clinic/libclinic/converters.py
@@ -30,7 +30,8 @@ class bool_converter(CConverter):
             fail(f"bool_converter: illegal 'accept' argument {accept!r}")
         if self.default is not unspecified and self.default is not unknown:
             self.default = bool(self.default)
-            self.c_default = str(int(self.default))
+            if self.c_default in {'Py_True', 'Py_False'}:
+                self.c_default = str(int(self.default))
 
     def parse_arg(self, argname: str, displayname: str, *, limited_capi: bool) -> str | None:
         if self.format_unit == 'i':