diff --git a/CHANGELOG.md b/CHANGELOG.md
index be323fd2eed..ab51bc2568b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Added
 - Add unsafe API `with_embedded_python_interpreter` to initalize a Python interpreter, execute a closure, and finalize the interpreter. [#1355](https://github.com/PyO3/pyo3/pull/1355)
 - Add `serde` feature to support `Serialize/Deserialize` for `Py<T>`. [#1366](https://github.com/PyO3/pyo3/pull/1366)
+- Add FFI definition `_PyCFunctionFastWithKeywords` on Python 3.7 and up. [#1384](https://github.com/PyO3/pyo3/pull/1384)
 
 ### Changed
 - `prepare_freethreaded_python` will no longer register an `atexit` handler to call `Py_Finalize`. [#1355](https://github.com/PyO3/pyo3/pull/1355)
diff --git a/src/ffi/methodobject.rs b/src/ffi/methodobject.rs
index c827f2741fc..fdf1797ea2a 100644
--- a/src/ffi/methodobject.rs
+++ b/src/ffi/methodobject.rs
@@ -30,6 +30,14 @@ pub type PyCFunctionWithKeywords = unsafe extern "C" fn(
     kwds: *mut PyObject,
 ) -> *mut PyObject;
 
+#[cfg(Py_3_7)]
+pub type _PyCFunctionFastWithKeywords = unsafe extern "C" fn(
+    slf: *mut PyObject,
+    args: *const *mut PyObject,
+    nargs: crate::ffi::pyport::Py_ssize_t,
+    kwnames: *mut PyObject,
+) -> *mut PyObject;
+
 extern "C" {
     #[cfg_attr(PyPy, link_name = "PyPyCFunction_GetFunction")]
     pub fn PyCFunction_GetFunction(f: *mut PyObject) -> Option<PyCFunction>;