diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -99,6 +99,12 @@ bytes(cdata)
  *
  */
 
+/*[clinic input]
+module ctypes
+class ctypes._CData
+[clinic start generated code]*/
+/*[clinic end generated code: checksum=da39a3ee5e6b4b0d3255bfef95601890afd80709]*/
+
 #define PY_SSIZE_T_CLEAN
 
 #include "Python.h"
@@ -414,25 +420,56 @@ CDataType_from_address(PyObject *type, P
     return PyCData_AtAddress(type, buf);
 }
 
-static char from_buffer_doc[] =
-"C.from_buffer(object, offset=0) -> C instance\ncreate a C instance from a writeable buffer";
-
 static int
 KeepRef(CDataObject *target, Py_ssize_t index, PyObject *keep);
 
+/*[clinic input]
+ctypes._CData.from_buffer
+
+  obj: object
+  offset: Py_ssize_t = 0
+  /
+
+Create an instance from a writeable buffer.
+[clinic start generated code]*/
+
+PyDoc_STRVAR(ctypes__CData_from_buffer__doc__,
+"from_buffer(obj, offset=0)\n"
+"Create an instance from a writeable buffer.");
+
+#define CTYPES__CDATA_FROM_BUFFER_METHODDEF    \
+    {"from_buffer", (PyCFunction)ctypes__CData_from_buffer, METH_VARARGS, ctypes__CData_from_buffer__doc__},
+
 static PyObject *
-CDataType_from_buffer(PyObject *type, PyObject *args)
+ctypes__CData_from_buffer_impl(PyObject *self, PyObject *obj, Py_ssize_t offset);
+
+static PyObject *
+ctypes__CData_from_buffer(PyObject *self, PyObject *args)
+{
+    PyObject *return_value = NULL;
+    PyObject *obj;
+    Py_ssize_t offset = 0;
+
+    if (!PyArg_ParseTuple(args,
+        "O|n:from_buffer",
+        &obj, &offset))
+        goto exit;
+    return_value = ctypes__CData_from_buffer_impl(self, obj, offset);
+
+exit:
+    return return_value;
+}
+
+static PyObject *
+ctypes__CData_from_buffer_impl(PyObject *self, PyObject *obj, Py_ssize_t offset)
+/*[clinic end generated code: checksum=e6f3fec7db52b61f5bd28b707656129213c4a14c]*/
 {
     void *buffer;
     Py_ssize_t buffer_len;
-    Py_ssize_t offset = 0;
-    PyObject *obj, *result;
-    StgDictObject *dict = PyType_stgdict(type);
+    PyObject *result;
+    StgDictObject *dict = PyType_stgdict(self);
     assert (dict);
 
-    if (!PyArg_ParseTuple(args, "O|n:from_buffer", &obj, &offset))
-        return NULL;
-
     if (-1 == PyObject_AsWriteBuffer(obj, &buffer, &buffer_len))
         return NULL;
 
@@ -448,7 +485,7 @@ CDataType_from_buffer(PyObject *type, Py
         return NULL;
     }
 
-    result = PyCData_AtAddress(type, (char *)buffer + offset);
+    result = PyCData_AtAddress(self, (char *)buffer + offset);
     if (result == NULL)
         return NULL;
 
@@ -459,25 +496,56 @@ CDataType_from_buffer(PyObject *type, Py
     return result;
 }
 
-static char from_buffer_copy_doc[] =
-"C.from_buffer_copy(object, offset=0) -> C instance\ncreate a C instance from a readable buffer";
-
 static PyObject *
 GenericPyCData_new(PyTypeObject *type, PyObject *args, PyObject *kwds);
 
+/*[clinic input]
+ctypes._CData.from_buffer_copy
+
+  obj: object
+  offset: Py_ssize_t = 0
+  /
+
+Create an instance from a readable buffer.
+[clinic start generated code]*/
+
+PyDoc_STRVAR(ctypes__CData_from_buffer_copy__doc__,
+"from_buffer_copy(obj, offset=0)\n"
+"Create an instance from a readable buffer.");
+
+#define CTYPES__CDATA_FROM_BUFFER_COPY_METHODDEF    \
+    {"from_buffer_copy", (PyCFunction)ctypes__CData_from_buffer_copy, METH_VARARGS, ctypes__CData_from_buffer_copy__doc__},
+
 static PyObject *
-CDataType_from_buffer_copy(PyObject *type, PyObject *args)
+ctypes__CData_from_buffer_copy_impl(PyObject *self, PyObject *obj, Py_ssize_t offset);
+
+static PyObject *
+ctypes__CData_from_buffer_copy(PyObject *self, PyObject *args)
+{
+    PyObject *return_value = NULL;
+    PyObject *obj;
+    Py_ssize_t offset = 0;
+
+    if (!PyArg_ParseTuple(args,
+        "O|n:from_buffer_copy",
+        &obj, &offset))
+        goto exit;
+    return_value = ctypes__CData_from_buffer_copy_impl(self, obj, offset);
+
+exit:
+    return return_value;
+}
+
+static PyObject *
+ctypes__CData_from_buffer_copy_impl(PyObject *self, PyObject *obj, Py_ssize_t offset)
+/*[clinic end generated code: checksum=bd2a97f3db2066ebbeab1647ae215eee575255b3]*/
 {
     const void *buffer;
     Py_ssize_t buffer_len;
-    Py_ssize_t offset = 0;
-    PyObject *obj, *result;
-    StgDictObject *dict = PyType_stgdict(type);
+    PyObject *result;
+    StgDictObject *dict = PyType_stgdict(self);
     assert (dict);
 
-    if (!PyArg_ParseTuple(args, "O|n:from_buffer", &obj, &offset))
-        return NULL;
-
     if (-1 == PyObject_AsReadBuffer(obj, (const void**)&buffer, &buffer_len))
         return NULL;
 
@@ -494,7 +562,7 @@ CDataType_from_buffer_copy(PyObject *typ
         return NULL;
     }
 
-    result = GenericPyCData_new((PyTypeObject *)type, NULL, NULL);
+    result = GenericPyCData_new((PyTypeObject *)self, NULL, NULL);
     if (result == NULL)
         return NULL;
     memcpy(((CDataObject *)result)->b_ptr,
@@ -502,21 +570,51 @@ CDataType_from_buffer_copy(PyObject *typ
     return result;
 }
 
-static char in_dll_doc[] =
-"C.in_dll(dll, name) -> C instance\naccess a C instance in a dll";
+/*[clinic input]
+ctypes._CData.in_dll
+
+  dll: object
+  name: str
+  /
+
+Access an instance in a dll.
+[clinic start generated code]*/
+
+PyDoc_STRVAR(ctypes__CData_in_dll__doc__,
+"in_dll(dll, name)\n"
+"Access an instance in a dll.");
+
+#define CTYPES__CDATA_IN_DLL_METHODDEF    \
+    {"in_dll", (PyCFunction)ctypes__CData_in_dll, METH_VARARGS, ctypes__CData_in_dll__doc__},
 
 static PyObject *
-CDataType_in_dll(PyObject *type, PyObject *args)
+ctypes__CData_in_dll_impl(PyObject *self, PyObject *dll, const char *name);
+
+static PyObject *
+ctypes__CData_in_dll(PyObject *self, PyObject *args)
 {
+    PyObject *return_value = NULL;
     PyObject *dll;
-    char *name;
+    const char *name;
+
+    if (!PyArg_ParseTuple(args,
+        "Os:in_dll",
+        &dll, &name))
+        goto exit;
+    return_value = ctypes__CData_in_dll_impl(self, dll, name);
+
+exit:
+    return return_value;
+}
+
+static PyObject *
+ctypes__CData_in_dll_impl(PyObject *self, PyObject *dll, const char *name)
+/*[clinic end generated code: checksum=104cfe5c306695d02999f77786e2ae553587892a]*/
+{
     PyObject *obj;
     void *handle;
     void *address;
 
-    if (!PyArg_ParseTuple(args, "Os:in_dll", &dll, &name))
-        return NULL;
-
     obj = PyObject_GetAttrString(dll, "_handle");
     if (!obj)
         return NULL;
@@ -556,7 +654,7 @@ CDataType_in_dll(PyObject *type, PyObjec
         return NULL;
     }
 #endif
-    return PyCData_AtAddress(type, address);
+    return PyCData_AtAddress(self, address);
 }
 
 static char from_param_doc[] =
@@ -614,9 +712,9 @@ CDataType_from_param(PyObject *type, PyO
 static PyMethodDef CDataType_methods[] = {
     { "from_param", CDataType_from_param, METH_O, from_param_doc },
     { "from_address", CDataType_from_address, METH_O, from_address_doc },
-    { "from_buffer", CDataType_from_buffer, METH_VARARGS, from_buffer_doc, },
-    { "from_buffer_copy", CDataType_from_buffer_copy, METH_VARARGS, from_buffer_copy_doc, },
-    { "in_dll", CDataType_in_dll, METH_VARARGS, in_dll_doc },
+    CTYPES__CDATA_FROM_BUFFER_METHODDEF
+    CTYPES__CDATA_FROM_BUFFER_COPY_METHODDEF
+    CTYPES__CDATA_IN_DLL_METHODDEF
     { NULL, NULL },
 };
 
@@ -960,9 +1058,9 @@ PyCPointerType_from_param(PyObject *type
 
 static PyMethodDef PyCPointerType_methods[] = {
     { "from_address", CDataType_from_address, METH_O, from_address_doc },
-    { "from_buffer", CDataType_from_buffer, METH_VARARGS, from_buffer_doc, },
-    { "from_buffer_copy", CDataType_from_buffer_copy, METH_VARARGS, from_buffer_copy_doc, },
-    { "in_dll", CDataType_in_dll, METH_VARARGS, in_dll_doc},
+    CTYPES__CDATA_FROM_BUFFER_METHODDEF
+    CTYPES__CDATA_FROM_BUFFER_COPY_METHODDEF
+    CTYPES__CDATA_IN_DLL_METHODDEF
     { "from_param", (PyCFunction)PyCPointerType_from_param, METH_O, from_param_doc},
     { "set_type", (PyCFunction)PyCPointerType_set_type, METH_O },
     { NULL, NULL },
@@ -2048,9 +2146,9 @@ PyCSimpleType_from_param(PyObject *type,
 static PyMethodDef PyCSimpleType_methods[] = {
     { "from_param", PyCSimpleType_from_param, METH_O, from_param_doc },
     { "from_address", CDataType_from_address, METH_O, from_address_doc },
-    { "from_buffer", CDataType_from_buffer, METH_VARARGS, from_buffer_doc, },
-    { "from_buffer_copy", CDataType_from_buffer_copy, METH_VARARGS, from_buffer_copy_doc, },
-    { "in_dll", CDataType_in_dll, METH_VARARGS, in_dll_doc},
+    CTYPES__CDATA_FROM_BUFFER_METHODDEF
+    CTYPES__CDATA_FROM_BUFFER_COPY_METHODDEF
+    CTYPES__CDATA_IN_DLL_METHODDEF
     { NULL, NULL },
 };