diff --git a/pyo3-ffi/src/lib.rs b/pyo3-ffi/src/lib.rs
index f37b758e..73ec459b 100644
--- a/pyo3-ffi/src/lib.rs
+++ b/pyo3-ffi/src/lib.rs
@@ -88,64 +88,40 @@
 //!
 //! use pyo3_ffi::*;
 //!
+//! static mut MODULE_DEF: PyModuleDef = PyModuleDef {
+//!     m_base: PyModuleDef_HEAD_INIT,
+//!     m_name: "string_sum\0".as_ptr().cast::<c_char>(),
+//!     m_doc: "A Python module written in Rust.\0"
+//!         .as_ptr()
+//!         .cast::<c_char>(),
+//!     m_size: 0,
+//!     m_methods: unsafe { METHODS.as_mut_ptr().cast() },
+//!     m_slots: std::ptr::null_mut(),
+//!     m_traverse: None,
+//!     m_clear: None,
+//!     m_free: None,
+//! };
+//!
+//! static mut METHODS: [PyMethodDef; 2] = [
+//!     PyMethodDef {
+//!         ml_name: "sum_as_string\0".as_ptr().cast::<c_char>(),
+//!         ml_meth: PyMethodDefPointer {
+//!             _PyCFunctionFast: sum_as_string,
+//!         },
+//!         ml_flags: METH_FASTCALL,
+//!         ml_doc: "returns the sum of two integers as a string\0"
+//!             .as_ptr()
+//!             .cast::<c_char>(),
+//!     },
+//!     // A zeroed PyMethodDef to mark the end of the array.
+//!     PyMethodDef::zeroed()
+//! ];
+//!
+//! // The module initialization function, which must be named `PyInit_<your_module>`.
 //! #[allow(non_snake_case)]
 //! #[no_mangle]
 //! pub unsafe extern "C" fn PyInit_string_sum() -> *mut PyObject {
-//!     let init = PyModuleDef {
-//!         m_base: PyModuleDef_HEAD_INIT,
-//!         m_name: "string_sum\0".as_ptr() as *const c_char,
-//!         m_doc: std::ptr::null(),
-//!         m_size: 0,
-//!         m_methods: std::ptr::null_mut(),
-//!         m_slots: std::ptr::null_mut(),
-//!         m_traverse: None,
-//!         m_clear: None,
-//!         m_free: None,
-//!     };
-//!
-//!     let mptr = PyModule_Create(Box::into_raw(Box::new(init)));
-//!     let version = env!("CARGO_PKG_VERSION");
-//!     PyModule_AddObject(
-//!         mptr,
-//!         "__version__\0".as_ptr() as *const c_char,
-//!         PyUnicode_FromStringAndSize(version.as_ptr() as *const c_char, version.len() as isize),
-//!     );
-//!
-//!     let wrapped_sum_as_string = PyMethodDef {
-//!         ml_name: "sum_as_string\0".as_ptr() as *const c_char,
-//!         ml_meth: PyMethodDefPointer {
-//!             _PyCFunctionFast: sum_as_string
-//!         },
-//!         ml_flags: METH_FASTCALL,
-//!         ml_doc: "returns the sum of two integers as a string\0".as_ptr() as *const c_char,
-//!     };
-//!
-//!     // PyModule_AddObject can technically fail.
-//!     // For more involved applications error checking may be necessary
-//!     PyModule_AddObject(
-//!         mptr,
-//!         "sum_as_string\0".as_ptr() as *const c_char,
-//!         PyCFunction_NewEx(
-//!             Box::into_raw(Box::new(wrapped_sum_as_string)),
-//!             std::ptr::null_mut(),
-//!             PyUnicode_InternFromString("string_sum\0".as_ptr() as *const c_char),
-//!         ),
-//!     );
-//!
-//!     let all = ["__all__\0", "__version__\0", "sum_as_string\0"];
-//!
-//!     let pyall = PyTuple_New(all.len() as isize);
-//!     for (i, obj) in all.iter().enumerate() {
-//!         PyTuple_SET_ITEM(
-//!             pyall,
-//!             i as isize,
-//!             PyUnicode_InternFromString(obj.as_ptr() as *const c_char),
-//!         )
-//!     }
-//!
-//!     PyModule_AddObject(mptr, "__all__\0".as_ptr() as *const c_char, pyall);
-//!
-//!     mptr
+//!     PyModule_Create(ptr::addr_of_mut!(MODULE_DEF))
 //! }
 //!
 //! pub unsafe extern "C" fn sum_as_string(
@@ -154,42 +130,60 @@
 //!     nargs: Py_ssize_t,
 //! ) -> *mut PyObject {
 //!     if nargs != 2 {
-//!         return raise_type_error("sum_as_string() expected 2 positional arguments");
+//!         PyErr_SetString(
+//!             PyExc_TypeError,
+//!             "sum_as_string() expected 2 positional arguments\0"
+//!                 .as_ptr()
+//!                 .cast::<c_char>(),
+//!         );
+//!         return std::ptr::null_mut();
 //!     }
 //!
 //!     let arg1 = *args;
 //!     if PyLong_Check(arg1) == 0 {
-//!         return raise_type_error("sum_as_string() expected an int for positional argument 1");
+//!         PyErr_SetString(
+//!             PyExc_TypeError,
+//!             "sum_as_string() expected an int for positional argument 1\0"
+//!                 .as_ptr()
+//!                 .cast::<c_char>(),
+//!         );
+//!         return std::ptr::null_mut();
 //!     }
 //!
 //!     let arg1 = PyLong_AsLong(arg1);
 //!     if !PyErr_Occurred().is_null() {
-//!         return ptr::null_mut()
+//!         return ptr::null_mut();
 //!     }
 //!
 //!     let arg2 = *args.add(1);
 //!     if PyLong_Check(arg2) == 0 {
-//!         return raise_type_error("sum_as_string() expected an int for positional argument 2");
+//!         PyErr_SetString(
+//!             PyExc_TypeError,
+//!             "sum_as_string() expected an int for positional argument 2\0"
+//!                 .as_ptr()
+//!                 .cast::<c_char>(),
+//!         );
+//!         return std::ptr::null_mut();
 //!     }
 //!
 //!     let arg2 = PyLong_AsLong(arg2);
 //!     if !PyErr_Occurred().is_null() {
-//!         return ptr::null_mut()
+//!         return ptr::null_mut();
 //!     }
-//!     let res = (arg1 + arg2).to_string();
-//!     PyUnicode_FromStringAndSize(res.as_ptr() as *const c_char, res.len() as isize)
-//! }
 //!
-//! #[cold]
-//! #[inline(never)]
-//! fn raise_type_error(msg: &str) -> *mut PyObject {
-//!     unsafe {
-//!         let err_msg =
-//!             PyUnicode_FromStringAndSize(msg.as_ptr() as *const c_char, msg.len() as isize);
-//!         PyErr_SetObject(PyExc_TypeError, err_msg);
-//!         Py_DECREF(err_msg);
-//!     };
-//!     std::ptr::null_mut()
+//!     match arg1.checked_add(arg2) {
+//!         Some(sum) => {
+//!             let string = sum.to_string();
+//!             PyUnicode_FromStringAndSize(string.as_ptr().cast::<c_char>(), string.len() as isize)
+//!         }
+//!         None => {
+//!             PyErr_SetString(
+//!                 PyExc_OverflowError,
+//!                 "arguments too large to add\0".as_ptr().cast::<c_char>(),
+//!             );
+//!             std::ptr::null_mut()
+//!         }
+//!     }
 //! }
 //! ```
 //!