diff --git a/CHANGELOG.md b/CHANGELOG.md
index e591e565..e02fd0d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -50,6 +50,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix FFI definition `PyFrameObject` having multiple incorrect members on various Python versions. [#2424](https://github.com/PyO3/pyo3/pull/2424)
 - Fix FFI definition `PyTypeObject` missing deprecated field `tp_print` on Python 3.8. [#2428](https://github.com/PyO3/pyo3/pull/2428)
 - Fix FFI definitions `PyDateTime_CAPI`. `PyDateTime_Date`, `PyASCIIObject`, `PyBaseExceptionObject`, `PyListObject`, and `PyTypeObject` on PyPy. [#2428](https://github.com/PyO3/pyo3/pull/2428)
+- Fix FFI definition `_inittab` field `initfunc` typo'd as `initfun`. [#2431](https://github.com/PyO3/pyo3/pull/2431)
+- Fix FFI definitions `_PyDateTime_BaseTime` and `_PyDateTime_BaseDateTime` incorrectly having `fold` member. [#2432](https://github.com/PyO3/pyo3/pull/2432)
 
 ## [0.16.5] - 2022-05-15
 
diff --git a/pyo3-ffi/src/cpython/code.rs b/pyo3-ffi/src/cpython/code.rs
index 69e4dd82..1c24f8d4 100644
--- a/pyo3-ffi/src/cpython/code.rs
+++ b/pyo3-ffi/src/cpython/code.rs
@@ -11,13 +11,15 @@ use std::os::raw::{c_char, c_int, c_uchar, c_void};
 #[cfg(all(Py_3_8, not(PyPy), not(Py_3_11)))]
 opaque_struct!(_PyOpcache);
 
+#[cfg(all(not(PyPy), not(Py_3_8)))]
+opaque_struct!(PyCodeObject);
+
 #[cfg(all(not(PyPy), Py_3_8, not(Py_3_11)))]
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub struct PyCodeObject {
     pub ob_base: PyObject,
     pub co_argcount: c_int,
-    #[cfg(Py_3_8)]
     pub co_posonlyargcount: c_int,
     pub co_kwonlyargcount: c_int,
     pub co_nlocals: c_int,
@@ -40,13 +42,9 @@ pub struct PyCodeObject {
     pub co_zombieframe: *mut c_void,
     pub co_weakreflist: *mut PyObject,
     pub co_extra: *mut c_void,
-    #[cfg(Py_3_8)]
     pub co_opcache_map: *mut c_uchar,
-    #[cfg(all(Py_3_8, not(Py_3_11)))]
     pub co_opcache: *mut _PyOpcache,
-    #[cfg(Py_3_8)]
     pub co_opcache_flag: c_int,
-    #[cfg(Py_3_8)]
     pub co_opcache_size: c_uchar,
 }
 
@@ -81,9 +79,6 @@ pub struct PyCodeObject {
     pub co_code_adaptive: [c_char; 1],
 }
 
-#[cfg(all(not(PyPy), Py_3_7, not(Py_3_8)))]
-opaque_struct!(PyCodeObject);
-
 #[cfg(PyPy)]
 #[repr(C)]
 #[derive(Copy, Clone)]
diff --git a/pyo3-ffi/src/cpython/genobject.rs b/pyo3-ffi/src/cpython/genobject.rs
index 88895a48..4d494be3 100644
--- a/pyo3-ffi/src/cpython/genobject.rs
+++ b/pyo3-ffi/src/cpython/genobject.rs
@@ -1,19 +1,14 @@
 use crate::object::*;
 use crate::PyFrameObject;
 #[cfg(not(PyPy))]
-use crate::{Py_ssize_t, _PyErr_StackItem};
+use crate::_PyErr_StackItem;
 use std::os::raw::c_int;
 
 #[cfg(not(PyPy))]
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub struct PyGenObject {
-    #[cfg(py_sys_config = "Py_TRACE_REFS")]
-    pub _ob_next: *mut PyObject,
-    #[cfg(py_sys_config = "Py_TRACE_REFS")]
-    pub _ob_prev: *mut PyObject,
-    pub ob_refcnt: Py_ssize_t,
-    pub ob_type: *mut PyTypeObject,
+    pub ob_base: PyObject,
     pub gi_frame: *mut PyFrameObject,
     #[cfg(not(Py_3_10))]
     pub gi_running: c_int,
diff --git a/pyo3-ffi/src/cpython/pyerrors.rs b/pyo3-ffi/src/cpython/pyerrors.rs
index 34497676..8464d4fa 100644
--- a/pyo3-ffi/src/cpython/pyerrors.rs
+++ b/pyo3-ffi/src/cpython/pyerrors.rs
@@ -24,7 +24,14 @@ pub struct PyBaseExceptionObject {
 #[repr(C)]
 #[derive(Debug)]
 pub struct PySyntaxErrorObject {
-    pub exception_base: PyBaseExceptionObject,
+    pub ob_base: PyObject,
+    pub dict: *mut PyObject,
+    pub args: *mut PyObject,
+    pub traceback: *mut PyObject,
+    pub context: *mut PyObject,
+    pub cause: *mut PyObject,
+    pub suppress_context: char,
+
     pub msg: *mut PyObject,
     pub filename: *mut PyObject,
     pub lineno: *mut PyObject,
@@ -41,7 +48,14 @@ pub struct PySyntaxErrorObject {
 #[repr(C)]
 #[derive(Debug)]
 pub struct PyImportErrorObject {
-    pub exception_base: PyBaseExceptionObject,
+    pub ob_base: PyObject,
+    pub dict: *mut PyObject,
+    pub args: *mut PyObject,
+    pub traceback: *mut PyObject,
+    pub context: *mut PyObject,
+    pub cause: *mut PyObject,
+    pub suppress_context: char,
+
     pub msg: *mut PyObject,
     pub name: *mut PyObject,
     pub path: *mut PyObject,
@@ -51,7 +65,14 @@ pub struct PyImportErrorObject {
 #[repr(C)]
 #[derive(Debug)]
 pub struct PyUnicodeErrorObject {
-    pub exception_base: PyBaseExceptionObject,
+    pub ob_base: PyObject,
+    pub dict: *mut PyObject,
+    pub args: *mut PyObject,
+    pub traceback: *mut PyObject,
+    pub context: *mut PyObject,
+    pub cause: *mut PyObject,
+    pub suppress_context: char,
+
     pub encoding: *mut PyObject,
     pub object: *mut PyObject,
     pub start: Py_ssize_t,
@@ -63,7 +84,14 @@ pub struct PyUnicodeErrorObject {
 #[repr(C)]
 #[derive(Debug)]
 pub struct PySystemExitObject {
-    pub exception_base: PyBaseExceptionObject,
+    pub ob_base: PyObject,
+    pub dict: *mut PyObject,
+    pub args: *mut PyObject,
+    pub traceback: *mut PyObject,
+    pub context: *mut PyObject,
+    pub cause: *mut PyObject,
+    pub suppress_context: char,
+
     pub code: *mut PyObject,
 }
 
@@ -71,7 +99,14 @@ pub struct PySystemExitObject {
 #[repr(C)]
 #[derive(Debug)]
 pub struct PyOSErrorObject {
-    pub exception_base: PyBaseExceptionObject,
+    pub ob_base: PyObject,
+    pub dict: *mut PyObject,
+    pub args: *mut PyObject,
+    pub traceback: *mut PyObject,
+    pub context: *mut PyObject,
+    pub cause: *mut PyObject,
+    pub suppress_context: char,
+
     pub myerrno: *mut PyObject,
     pub strerror: *mut PyObject,
     pub filename: *mut PyObject,
@@ -84,7 +119,14 @@ pub struct PyOSErrorObject {
 #[repr(C)]
 #[derive(Debug)]
 pub struct PyStopIterationObject {
-    pub exception_base: PyBaseExceptionObject,
+    pub ob_base: PyObject,
+    pub dict: *mut PyObject,
+    pub args: *mut PyObject,
+    pub traceback: *mut PyObject,
+    pub context: *mut PyObject,
+    pub cause: *mut PyObject,
+    pub suppress_context: char,
+
     pub value: *mut PyObject,
 }
 
diff --git a/pyo3-ffi/src/datetime.rs b/pyo3-ffi/src/datetime.rs
index 112d9b24..8f552831 100644
--- a/pyo3-ffi/src/datetime.rs
+++ b/pyo3-ffi/src/datetime.rs
@@ -51,8 +51,6 @@ pub struct _PyDateTime_BaseTime {
     pub hastzinfo: c_char,
     #[cfg(not(PyPy))]
     pub data: [c_uchar; _PyDateTime_TIME_DATASIZE],
-    #[cfg(not(PyPy))]
-    pub fold: c_uchar,
 }
 
 #[repr(C)]
@@ -98,8 +96,6 @@ pub struct _PyDateTime_BaseDateTime {
     pub hastzinfo: c_char,
     #[cfg(not(PyPy))]
     pub data: [c_uchar; _PyDateTime_DATETIME_DATASIZE],
-    #[cfg(not(PyPy))]
-    pub fold: c_uchar,
 }
 
 #[repr(C)]