diff --git a/pyo3-ffi/src/abstract_.rs b/pyo3-ffi/src/abstract_.rs
index 8f2b4831231..a1eb2366d43 100644
--- a/pyo3-ffi/src/abstract_.rs
+++ b/pyo3-ffi/src/abstract_.rs
@@ -54,21 +54,13 @@ extern "C" {
         ...
     ) -> *mut PyObject;
 
-    #[cfg(not(Py_3_13))]
+    #[cfg(PyPy)]
     #[cfg_attr(PyPy, link_name = "_PyPyObject_CallFunction_SizeT")]
-    pub fn _PyObject_CallFunction_SizeT(
+    pub(crate) fn _PyObject_CallFunction_SizeT(
         callable_object: *mut PyObject,
         format: *const c_char,
         ...
     ) -> *mut PyObject;
-    #[cfg(not(Py_3_13))]
-    #[cfg_attr(PyPy, link_name = "_PyPyObject_CallMethod_SizeT")]
-    pub fn _PyObject_CallMethod_SizeT(
-        o: *mut PyObject,
-        method: *const c_char,
-        format: *const c_char,
-        ...
-    ) -> *mut PyObject;
 
     #[cfg_attr(PyPy, link_name = "PyPyObject_CallFunctionObjArgs")]
     pub fn PyObject_CallFunctionObjArgs(callable: *mut PyObject, ...) -> *mut PyObject;
diff --git a/pyo3-ffi/src/cpython/abstract_.rs b/pyo3-ffi/src/cpython/abstract_.rs
index 53ef71e0710..a20bf19b190 100644
--- a/pyo3-ffi/src/cpython/abstract_.rs
+++ b/pyo3-ffi/src/cpython/abstract_.rs
@@ -14,17 +14,14 @@ use crate::{
 #[cfg(Py_3_8)]
 use libc::size_t;
 
-extern "C" {
-    #[cfg(all(Py_3_8, not(any(PyPy, GraalPy))))]
-    pub fn _PyStack_AsDict(values: *const *mut PyObject, kwnames: *mut PyObject) -> *mut PyObject;
-}
+// skipped private _PyStack_AsDict
 
 #[cfg(all(Py_3_8, not(any(PyPy, GraalPy))))]
 const _PY_FASTCALL_SMALL_STACK: size_t = 5;
 
 extern "C" {
     #[cfg(all(Py_3_8, not(PyPy)))]
-    pub fn _Py_CheckFunctionResult(
+    fn _Py_CheckFunctionResult(
         tstate: *mut PyThreadState,
         callable: *mut PyObject,
         result: *mut PyObject,
@@ -32,7 +29,7 @@ extern "C" {
     ) -> *mut PyObject;
 
     #[cfg(all(Py_3_8, not(PyPy)))]
-    pub fn _PyObject_MakeTpCall(
+    fn _PyObject_MakeTpCall(
         tstate: *mut PyThreadState,
         callable: *mut PyObject,
         args: *const *mut PyObject,
@@ -69,7 +66,7 @@ pub unsafe fn PyVectorcall_Function(callable: *mut PyObject) -> Option<vectorcal
 
 #[cfg(all(Py_3_8, not(PyPy)))]
 #[inline(always)]
-pub unsafe fn _PyObject_VectorcallTstate(
+unsafe fn _PyObject_VectorcallTstate(
     tstate: *mut PyThreadState,
     callable: *mut PyObject,
     args: *const *mut PyObject,
@@ -127,44 +124,9 @@ extern "C" {
     ) -> *mut PyObject;
 }
 
-#[cfg(all(Py_3_8, not(any(PyPy, GraalPy))))]
-#[inline(always)]
-pub unsafe fn _PyObject_FastCallTstate(
-    tstate: *mut PyThreadState,
-    func: *mut PyObject,
-    args: *const *mut PyObject,
-    nargs: Py_ssize_t,
-) -> *mut PyObject {
-    _PyObject_VectorcallTstate(tstate, func, args, nargs as size_t, std::ptr::null_mut())
-}
-
-#[cfg(all(Py_3_8, not(any(PyPy, GraalPy))))]
-#[inline(always)]
-pub unsafe fn _PyObject_FastCall(
-    func: *mut PyObject,
-    args: *const *mut PyObject,
-    nargs: Py_ssize_t,
-) -> *mut PyObject {
-    _PyObject_FastCallTstate(PyThreadState_GET(), func, args, nargs)
-}
-
-#[cfg(all(Py_3_8, not(PyPy)))]
-#[inline(always)]
-pub unsafe fn _PyObject_CallNoArg(func: *mut PyObject) -> *mut PyObject {
-    _PyObject_VectorcallTstate(
-        PyThreadState_GET(),
-        func,
-        std::ptr::null_mut(),
-        0,
-        std::ptr::null_mut(),
-    )
-}
-
-extern "C" {
-    #[cfg(PyPy)]
-    #[link_name = "_PyPyObject_CallNoArg"]
-    pub fn _PyObject_CallNoArg(func: *mut PyObject) -> *mut PyObject;
-}
+// skipped private _PyObject_FastCallTstate
+// skipped private _PyObject_FastCall
+// skipped private _PyObject_CallNoArg
 
 #[cfg(all(Py_3_8, not(PyPy)))]
 #[inline(always)]
@@ -290,14 +252,7 @@ pub const PY_ITERSEARCH_COUNT: c_int = 1;
 pub const PY_ITERSEARCH_INDEX: c_int = 2;
 pub const PY_ITERSEARCH_CONTAINS: c_int = 3;
 
-extern "C" {
-    #[cfg(not(any(PyPy, GraalPy)))]
-    pub fn _PySequence_IterSearch(
-        seq: *mut PyObject,
-        obj: *mut PyObject,
-        operation: c_int,
-    ) -> Py_ssize_t;
-}
+// skipped private _PySequence_IterSearch
 
 // skipped _PyObject_RealIsInstance
 // skipped _PyObject_RealIsSubclass
diff --git a/pyo3-ffi/src/cpython/bytesobject.rs b/pyo3-ffi/src/cpython/bytesobject.rs
index 56344d35dd9..8acaaf270a6 100644
--- a/pyo3-ffi/src/cpython/bytesobject.rs
+++ b/pyo3-ffi/src/cpython/bytesobject.rs
@@ -1,8 +1,6 @@
 use crate::object::*;
-use crate::Py_ssize_t;
 #[cfg(not(Py_LIMITED_API))]
 use std::ffi::c_char;
-use std::ffi::c_int;
 
 #[cfg(not(any(PyPy, GraalPy, Py_LIMITED_API)))]
 #[repr(C)]
@@ -19,10 +17,7 @@ pub struct PyBytesObject {
 #[cfg(any(PyPy, GraalPy, Py_LIMITED_API))]
 opaque_struct!(pub PyBytesObject);
 
-extern "C" {
-    #[cfg_attr(PyPy, link_name = "_PyPyBytes_Resize")]
-    pub fn _PyBytes_Resize(bytes: *mut *mut PyObject, newsize: Py_ssize_t) -> c_int;
-}
+// skipped private _PyBytes_Resize
 
 #[cfg(not(Py_LIMITED_API))]
 #[inline]
diff --git a/pyo3-ffi/src/cpython/ceval.rs b/pyo3-ffi/src/cpython/ceval.rs
index cbec47195ec..502f33b7e55 100644
--- a/pyo3-ffi/src/cpython/ceval.rs
+++ b/pyo3-ffi/src/cpython/ceval.rs
@@ -1,21 +1,13 @@
 use crate::cpython::pystate::Py_tracefunc;
-use crate::object::{freefunc, PyObject};
-use std::ffi::c_int;
+use crate::object::PyObject;
 
 extern "C" {
-    // skipped non-limited _PyEval_CallTracing
+    // skipped private _PyEval_CallTracing
 
-    #[cfg(not(Py_3_11))]
-    pub fn _PyEval_EvalFrameDefault(arg1: *mut crate::PyFrameObject, exc: c_int) -> *mut PyObject;
+    // skipped private _PyEval_EvalFrameDefault
 
-    #[cfg(Py_3_11)]
-    pub fn _PyEval_EvalFrameDefault(
-        tstate: *mut crate::PyThreadState,
-        frame: *mut crate::_PyInterpreterFrame,
-        exc: c_int,
-    ) -> *mut crate::PyObject;
+    // skipped private _PyEval_RequestCodeExtraIndex
 
-    pub fn _PyEval_RequestCodeExtraIndex(func: freefunc) -> c_int;
     pub fn PyEval_SetProfile(trace_func: Option<Py_tracefunc>, arg1: *mut PyObject);
     pub fn PyEval_SetTrace(trace_func: Option<Py_tracefunc>, arg1: *mut PyObject);
 }
diff --git a/pyo3-ffi/src/cpython/code.rs b/pyo3-ffi/src/cpython/code.rs
index 3be303fb38a..ff655ba68c9 100644
--- a/pyo3-ffi/src/cpython/code.rs
+++ b/pyo3-ffi/src/cpython/code.rs
@@ -144,10 +144,7 @@ extern "C" {
         names: *mut PyObject,
         lnotab: *mut PyObject,
     ) -> *mut PyObject;
-    pub fn _PyCode_GetExtra(
-        code: *mut PyObject,
-        index: Py_ssize_t,
-        extra: *const *mut c_void,
-    ) -> c_int;
-    pub fn _PyCode_SetExtra(code: *mut PyObject, index: Py_ssize_t, extra: *mut c_void) -> c_int;
+
+    // skipped private _Py_GetExtra
+    // skipped private _Py_SetExtra
 }
diff --git a/pyo3-ffi/src/cpython/import.rs b/pyo3-ffi/src/cpython/import.rs
index 3b9374f68e3..3fd63a03739 100644
--- a/pyo3-ffi/src/cpython/import.rs
+++ b/pyo3-ffi/src/cpython/import.rs
@@ -6,27 +6,14 @@ use std::ffi::{c_char, c_int};
 // skipped PyInit__imp
 
 extern "C" {
-    pub fn _PyImport_IsInitialized(state: *mut PyInterpreterState) -> c_int;
+    // skipped private _PyImport_IsInitialized
     // skipped _PyImport_GetModuleId
-    pub fn _PyImport_SetModule(name: *mut PyObject, module: *mut PyObject) -> c_int;
-    pub fn _PyImport_SetModuleString(name: *const c_char, module: *mut PyObject) -> c_int;
-    pub fn _PyImport_AcquireLock();
-    pub fn _PyImport_ReleaseLock() -> c_int;
-    #[cfg(not(Py_3_9))]
-    pub fn _PyImport_FindBuiltin(name: *const c_char, modules: *mut PyObject) -> *mut PyObject;
-    #[cfg(not(Py_3_11))]
-    pub fn _PyImport_FindExtensionObject(a: *mut PyObject, b: *mut PyObject) -> *mut PyObject;
-    pub fn _PyImport_FixupBuiltin(
-        module: *mut PyObject,
-        name: *const c_char,
-        modules: *mut PyObject,
-    ) -> c_int;
-    pub fn _PyImport_FixupExtensionObject(
-        a: *mut PyObject,
-        b: *mut PyObject,
-        c: *mut PyObject,
-        d: *mut PyObject,
-    ) -> c_int;
+    // skipped private _PyImport_SetModule
+    // skipped private _PyImport_SetModuleString
+    // skipped private _PyImport_AcquireLock
+    // skipped private _PyImport_ReleaseLock
+    // skipped private _PyImport_FixupBuiltin
+    // skipped private _PyImport_FixupExtensionObject
 }
 
 #[cfg(not(PyPy))]
diff --git a/pyo3-ffi/src/cpython/initconfig.rs b/pyo3-ffi/src/cpython/initconfig.rs
index 6b0ae2e5dec..8c8bad64ee0 100644
--- a/pyo3-ffi/src/cpython/initconfig.rs
+++ b/pyo3-ffi/src/cpython/initconfig.rs
@@ -6,7 +6,7 @@ use std::ffi::{c_char, c_int, c_ulong};
 
 #[repr(C)]
 #[derive(Copy, Clone, Debug, PartialEq, Eq)]
-pub enum _PyStatus_TYPE {
+enum _PyStatus_TYPE {
     _PyStatus_TYPE_OK = 0,
     _PyStatus_TYPE_ERROR = 1,
     _PyStatus_TYPE_EXIT = 2,
@@ -15,7 +15,7 @@ pub enum _PyStatus_TYPE {
 #[repr(C)]
 #[derive(Copy, Clone)]
 pub struct PyStatus {
-    pub _type: _PyStatus_TYPE,
+    _type: _PyStatus_TYPE,
     pub func: *const c_char,
     pub err_msg: *const c_char,
     pub exitcode: c_int,
diff --git a/pyo3-ffi/src/cpython/objimpl.rs b/pyo3-ffi/src/cpython/objimpl.rs
index 71087d28d2c..0275c966e65 100644
--- a/pyo3-ffi/src/cpython/objimpl.rs
+++ b/pyo3-ffi/src/cpython/objimpl.rs
@@ -10,11 +10,6 @@ use crate::object::*;
 // skipped _PyObject_SIZE
 // skipped _PyObject_VAR_SIZE
 
-#[cfg(not(Py_3_11))]
-extern "C" {
-    pub fn _Py_GetAllocatedBlocks() -> crate::Py_ssize_t;
-}
-
 #[cfg(not(any(PyPy, GraalPy)))]
 #[repr(C)]
 #[derive(Copy, Clone)]
@@ -52,12 +47,6 @@ pub unsafe fn PyObject_IS_GC(o: *mut PyObject) -> c_int {
         }) as c_int
 }
 
-#[cfg(not(Py_3_11))]
-extern "C" {
-    pub fn _PyObject_GC_Malloc(size: size_t) -> *mut PyObject;
-    pub fn _PyObject_GC_Calloc(size: size_t) -> *mut PyObject;
-}
-
 #[inline]
 pub unsafe fn PyType_SUPPORTS_WEAKREFS(t: *mut PyTypeObject) -> c_int {
     ((*t).tp_weaklistoffset > 0) as c_int
diff --git a/pyo3-ffi/src/cpython/pyframe.rs b/pyo3-ffi/src/cpython/pyframe.rs
index 6da9ecd5b53..a6f3b54091f 100644
--- a/pyo3-ffi/src/cpython/pyframe.rs
+++ b/pyo3-ffi/src/cpython/pyframe.rs
@@ -6,9 +6,7 @@ use std::ffi::c_char;
 use std::ffi::c_int;
 use std::ptr::addr_of_mut;
 
-// NB used in `_PyEval_EvalFrameDefault`, maybe we remove this too.
-#[cfg(all(Py_3_11, not(PyPy)))]
-opaque_struct!(pub _PyInterpreterFrame);
+// skipped private _PyInterpreterFrame
 
 #[cfg_attr(windows, link(name = "pythonXY"))]
 extern "C" {
diff --git a/pyo3-ffi/src/cpython/pythonrun.rs b/pyo3-ffi/src/cpython/pythonrun.rs
index db3767cb60c..3e6560fc6ab 100644
--- a/pyo3-ffi/src/cpython/pythonrun.rs
+++ b/pyo3-ffi/src/cpython/pythonrun.rs
@@ -9,7 +9,7 @@ use std::ffi::{c_char, c_int};
 
 extern "C" {
     pub fn PyRun_SimpleStringFlags(arg1: *const c_char, arg2: *mut PyCompilerFlags) -> c_int;
-    pub fn _PyRun_SimpleFileObject(
+    fn _PyRun_SimpleFileObject(
         fp: *mut FILE,
         filename: *mut PyObject,
         closeit: c_int,
@@ -21,7 +21,7 @@ extern "C" {
         closeit: c_int,
         flags: *mut PyCompilerFlags,
     ) -> c_int;
-    pub fn _PyRun_AnyFileObject(
+    fn _PyRun_AnyFileObject(
         fp: *mut FILE,
         filename: *mut PyObject,
         closeit: c_int,
@@ -48,7 +48,7 @@ extern "C" {
         filename: *const c_char,
         flags: *mut PyCompilerFlags,
     ) -> c_int;
-    pub fn _PyRun_InteractiveLoopObject(
+    fn _PyRun_InteractiveLoopObject(
         fp: *mut FILE,
         filename: *mut PyObject,
         flags: *mut PyCompilerFlags,
diff --git a/pyo3-ffi/src/cpython/unicodeobject.rs b/pyo3-ffi/src/cpython/unicodeobject.rs
index cf0ef54484e..cba8c9bfa62 100644
--- a/pyo3-ffi/src/cpython/unicodeobject.rs
+++ b/pyo3-ffi/src/cpython/unicodeobject.rs
@@ -460,7 +460,7 @@ pub struct PyUnicodeObject {
 
 extern "C" {
     #[cfg(not(any(PyPy, GraalPy)))]
-    pub fn _PyUnicode_CheckConsistency(op: *mut PyObject, check_content: c_int) -> c_int;
+    fn _PyUnicode_CheckConsistency(op: *mut PyObject, check_content: c_int) -> c_int;
 }
 
 // skipped PyUnicode_GET_SIZE
@@ -538,9 +538,9 @@ pub unsafe fn PyUnicode_KIND(op: *mut PyObject) -> c_uint {
     (*(op as *mut PyASCIIObject)).kind()
 }
 
-#[cfg(not(any(GraalPy, Py_3_14)))]
+#[cfg(not(any(GraalPy, PyPy, Py_3_14)))]
 #[inline]
-pub unsafe fn _PyUnicode_COMPACT_DATA(op: *mut PyObject) -> *mut c_void {
+unsafe fn _PyUnicode_COMPACT_DATA(op: *mut PyObject) -> *mut c_void {
     if PyUnicode_IS_ASCII(op) != 0 {
         (op as *mut PyASCIIObject).offset(1) as *mut c_void
     } else {
@@ -548,9 +548,9 @@ pub unsafe fn _PyUnicode_COMPACT_DATA(op: *mut PyObject) -> *mut c_void {
     }
 }
 
-#[cfg(not(any(GraalPy, PyPy)))]
+#[cfg(not(any(GraalPy, PyPy, Py_3_14)))]
 #[inline]
-pub unsafe fn _PyUnicode_NONCOMPACT_DATA(op: *mut PyObject) -> *mut c_void {
+unsafe fn _PyUnicode_NONCOMPACT_DATA(op: *mut PyObject) -> *mut c_void {
     debug_assert!(!(*(op as *mut PyUnicodeObject)).data.any.is_null());
 
     (*(op as *mut PyUnicodeObject)).data.any
@@ -628,7 +628,8 @@ extern "C" {
     #[cfg_attr(PyPy, link_name = "PyPyUnicode_New")]
     pub fn PyUnicode_New(size: Py_ssize_t, maxchar: Py_UCS4) -> *mut PyObject;
     #[cfg_attr(PyPy, link_name = "_PyPyUnicode_Ready")]
-    pub fn _PyUnicode_Ready(unicode: *mut PyObject) -> c_int;
+    #[cfg(not(any(Py_3_12, GraalPy)))]
+    fn _PyUnicode_Ready(unicode: *mut PyObject) -> c_int;
 
     // skipped _PyUnicode_Copy
 
diff --git a/pyo3-ffi/src/datetime.rs b/pyo3-ffi/src/datetime.rs
index dc3a8b32dec..e3a356eca5f 100644
--- a/pyo3-ffi/src/datetime.rs
+++ b/pyo3-ffi/src/datetime.rs
@@ -33,19 +33,10 @@ pub struct PyDateTime_Delta {
     pub microseconds: c_int,
 }
 
-// skipped non-limited PyDateTime_TZInfo
-// skipped non-limited _PyDateTime_BaseTZInfo
+// skipped PyDateTime_TZInfo
+// skipped private _PyDateTime_BaseTZInfo
 
-#[cfg(not(any(PyPy, GraalPy)))]
-#[repr(C)]
-#[derive(Debug)]
-/// Structure representing a `datetime.time` without a `tzinfo` member.
-pub struct _PyDateTime_BaseTime {
-    pub ob_base: PyObject,
-    pub hashcode: Py_hash_t,
-    pub hastzinfo: c_char,
-    pub data: [c_uchar; _PyDateTime_TIME_DATASIZE],
-}
+// skipped private _PyDateTime_BaseTime
 
 #[repr(C)]
 #[derive(Debug)]
@@ -79,16 +70,7 @@ pub struct PyDateTime_Date {
     pub data: [c_uchar; _PyDateTime_DATE_DATASIZE],
 }
 
-#[cfg(not(any(PyPy, GraalPy)))]
-#[repr(C)]
-#[derive(Debug)]
-/// Structure representing a `datetime.datetime` without a `tzinfo` member.
-pub struct _PyDateTime_BaseDateTime {
-    pub ob_base: PyObject,
-    pub hashcode: Py_hash_t,
-    pub hastzinfo: c_char,
-    pub data: [c_uchar; _PyDateTime_DATETIME_DATASIZE],
-}
+// skipped private _PyDateTime_BaseDateTime
 
 #[repr(C)]
 #[derive(Debug)]
@@ -469,7 +451,7 @@ pub unsafe fn PyDateTime_DELTA_GET_MICROSECONDS(o: *mut PyObject) -> c_int {
 
 #[cfg(PyPy)]
 extern "C" {
-    // skipped _PyDateTime_HAS_TZINFO (not in PyPy)
+    // skipped private _PyDateTime_HAS_TZINFO
     #[link_name = "PyPyDateTime_GET_YEAR"]
     pub fn PyDateTime_GET_YEAR(o: *mut PyObject) -> c_int;
     #[link_name = "PyPyDateTime_GET_MONTH"]
diff --git a/pyo3-ffi/src/pyerrors.rs b/pyo3-ffi/src/pyerrors.rs
index 557f314c7cb..47ec5b98e96 100644
--- a/pyo3-ffi/src/pyerrors.rs
+++ b/pyo3-ffi/src/pyerrors.rs
@@ -298,9 +298,25 @@ extern "C" {
         arg2: *mut PyObject,
         arg3: *mut PyObject,
     ) -> *mut PyObject;
+    #[cfg(PyPy)]
     #[cfg_attr(PyPy, link_name = "PyPyErr_BadInternalCall")]
     pub fn PyErr_BadInternalCall();
-    pub fn _PyErr_BadInternalCall(filename: *const c_char, lineno: c_int);
+    #[cfg(not(PyPy))]
+    fn _PyErr_BadInternalCall(filename: *const c_char, lineno: c_int);
+}
+
+#[inline]
+#[cfg(not(PyPy))]
+#[track_caller]
+pub unsafe fn PyErr_BadInternalCall() {
+    let location = std::panic::Location::caller();
+    // TODO: nightly API file_as_c_str could be used here
+    let filename = std::ffi::CString::new(location.file()).ok();
+    let lineno = location.line().try_into().unwrap_or(0);
+    _PyErr_BadInternalCall(filename.as_deref().unwrap_or(c"<unknown>").as_ptr(), lineno);
+}
+
+extern "C" {
     #[cfg_attr(PyPy, link_name = "PyPyErr_NewException")]
     pub fn PyErr_NewException(
         name: *const c_char,
@@ -316,6 +332,7 @@ extern "C" {
     ) -> *mut PyObject;
     #[cfg_attr(PyPy, link_name = "PyPyErr_WriteUnraisable")]
     pub fn PyErr_WriteUnraisable(arg1: *mut PyObject);
+
     #[cfg_attr(PyPy, link_name = "PyPyErr_CheckSignals")]
     pub fn PyErr_CheckSignals() -> c_int;
     #[cfg_attr(PyPy, link_name = "PyPyErr_SetInterrupt")]
@@ -323,12 +340,14 @@ extern "C" {
     #[cfg(Py_3_10)]
     #[cfg_attr(PyPy, link_name = "PyPyErr_SetInterruptEx")]
     pub fn PyErr_SetInterruptEx(signum: c_int);
+
     #[cfg_attr(PyPy, link_name = "PyPyErr_SyntaxLocation")]
     pub fn PyErr_SyntaxLocation(filename: *const c_char, lineno: c_int);
     #[cfg_attr(PyPy, link_name = "PyPyErr_SyntaxLocationEx")]
     pub fn PyErr_SyntaxLocationEx(filename: *const c_char, lineno: c_int, col_offset: c_int);
     #[cfg_attr(PyPy, link_name = "PyPyErr_ProgramText")]
     pub fn PyErr_ProgramText(filename: *const c_char, lineno: c_int) -> *mut PyObject;
+
     #[cfg(not(PyPy))]
     pub fn PyUnicodeDecodeError_Create(
         encoding: *const c_char,
@@ -338,27 +357,38 @@ extern "C" {
         end: Py_ssize_t,
         reason: *const c_char,
     ) -> *mut PyObject;
+
     pub fn PyUnicodeEncodeError_GetEncoding(arg1: *mut PyObject) -> *mut PyObject;
     pub fn PyUnicodeDecodeError_GetEncoding(arg1: *mut PyObject) -> *mut PyObject;
+
     pub fn PyUnicodeEncodeError_GetObject(arg1: *mut PyObject) -> *mut PyObject;
     pub fn PyUnicodeDecodeError_GetObject(arg1: *mut PyObject) -> *mut PyObject;
     pub fn PyUnicodeTranslateError_GetObject(arg1: *mut PyObject) -> *mut PyObject;
+
     pub fn PyUnicodeEncodeError_GetStart(arg1: *mut PyObject, arg2: *mut Py_ssize_t) -> c_int;
     pub fn PyUnicodeDecodeError_GetStart(arg1: *mut PyObject, arg2: *mut Py_ssize_t) -> c_int;
     pub fn PyUnicodeTranslateError_GetStart(arg1: *mut PyObject, arg2: *mut Py_ssize_t) -> c_int;
+
     pub fn PyUnicodeEncodeError_SetStart(arg1: *mut PyObject, arg2: Py_ssize_t) -> c_int;
     pub fn PyUnicodeDecodeError_SetStart(arg1: *mut PyObject, arg2: Py_ssize_t) -> c_int;
     pub fn PyUnicodeTranslateError_SetStart(arg1: *mut PyObject, arg2: Py_ssize_t) -> c_int;
+
     pub fn PyUnicodeEncodeError_GetEnd(arg1: *mut PyObject, arg2: *mut Py_ssize_t) -> c_int;
     pub fn PyUnicodeDecodeError_GetEnd(arg1: *mut PyObject, arg2: *mut Py_ssize_t) -> c_int;
     pub fn PyUnicodeTranslateError_GetEnd(arg1: *mut PyObject, arg2: *mut Py_ssize_t) -> c_int;
+
     pub fn PyUnicodeEncodeError_SetEnd(arg1: *mut PyObject, arg2: Py_ssize_t) -> c_int;
     pub fn PyUnicodeDecodeError_SetEnd(arg1: *mut PyObject, arg2: Py_ssize_t) -> c_int;
     pub fn PyUnicodeTranslateError_SetEnd(arg1: *mut PyObject, arg2: Py_ssize_t) -> c_int;
+
     pub fn PyUnicodeEncodeError_GetReason(arg1: *mut PyObject) -> *mut PyObject;
     pub fn PyUnicodeDecodeError_GetReason(arg1: *mut PyObject) -> *mut PyObject;
     pub fn PyUnicodeTranslateError_GetReason(arg1: *mut PyObject) -> *mut PyObject;
+
     pub fn PyUnicodeEncodeError_SetReason(exc: *mut PyObject, reason: *const c_char) -> c_int;
     pub fn PyUnicodeDecodeError_SetReason(exc: *mut PyObject, reason: *const c_char) -> c_int;
     pub fn PyUnicodeTranslateError_SetReason(exc: *mut PyObject, reason: *const c_char) -> c_int;
+
+    // skipped PyOS_snprintf
+    // skipped PyOS_vsnprintf
 }
diff --git a/pyo3-ffi/src/pyhash.rs b/pyo3-ffi/src/pyhash.rs
index 4fab07d00d4..f089e3a1bd1 100644
--- a/pyo3-ffi/src/pyhash.rs
+++ b/pyo3-ffi/src/pyhash.rs
@@ -3,7 +3,7 @@ use crate::pyport::{Py_hash_t, Py_ssize_t};
 #[cfg(not(any(Py_LIMITED_API, PyPy)))]
 use std::ffi::c_void;
 
-use std::ffi::{c_int, c_ulong};
+use std::ffi::c_int;
 
 extern "C" {
     // skipped non-limited _Py_HashDouble
@@ -11,14 +11,12 @@ extern "C" {
     // skipped non-limited _Py_HashPointerRaw
 
     #[cfg(not(any(Py_LIMITED_API, PyPy)))]
-    pub fn _Py_HashBytes(src: *const c_void, len: Py_ssize_t) -> Py_hash_t;
+    pub(crate) fn _Py_HashBytes(src: *const c_void, len: Py_ssize_t) -> Py_hash_t;
 }
 
-pub const _PyHASH_MULTIPLIER: c_ulong = 1000003;
-
-// skipped _PyHASH_BITS
-
-// skipped non-limited _Py_HashSecret_t
+// skipped private _PyHASH_MULTIPLIER
+// skipped private _PyHASH_BITS
+// skipped private _Py_HashSecret_t
 
 // skipped Py_HASH_CUTOFF
 
diff --git a/pyo3-ffi/src/setobject.rs b/pyo3-ffi/src/setobject.rs
index 4c32952238c..43b5517cb16 100644
--- a/pyo3-ffi/src/setobject.rs
+++ b/pyo3-ffi/src/setobject.rs
@@ -41,18 +41,8 @@ pub unsafe fn PySet_GET_SIZE(so: *mut PyObject) -> Py_ssize_t {
 
 // skipped _PySet_Dummy
 
-extern "C" {
-    #[cfg(not(Py_LIMITED_API))]
-    #[cfg_attr(PyPy, link_name = "_PyPySet_NextEntry")]
-    pub fn _PySet_NextEntry(
-        set: *mut PyObject,
-        pos: *mut Py_ssize_t,
-        key: *mut *mut PyObject,
-        hash: *mut super::Py_hash_t,
-    ) -> c_int;
-
-    // skipped non-limited _PySet_Update
-}
+// skipped private _PySet_NextEntry
+// skipped private _PySet_Update
 
 #[cfg_attr(windows, link(name = "pythonXY"))]
 extern "C" {