diff --git a/pyo3-ffi/src/methodobject.rs b/pyo3-ffi/src/methodobject.rs
index af027407f2c..6212090febb 100644
--- a/pyo3-ffi/src/methodobject.rs
+++ b/pyo3-ffi/src/methodobject.rs
@@ -36,7 +36,6 @@ pub type _PyCFunctionFast = unsafe extern "C" fn(
     slf: *mut PyObject,
     args: *mut *mut PyObject,
     nargs: crate::pyport::Py_ssize_t,
-    kwnames: *mut PyObject,
 ) -> *mut PyObject;
 
 pub type PyCFunctionWithKeywords = unsafe extern "C" fn(