diff --git a/include/pybind11/detail/type_caster_base.h b/include/pybind11/detail/type_caster_base.h
index ff7d7cf8c..a4154136a 100644
--- a/include/pybind11/detail/type_caster_base.h
+++ b/include/pybind11/detail/type_caster_base.h
@@ -502,9 +502,10 @@ PYBIND11_NOINLINE std::string error_string() {
         }
 
         PyFrameObject *frame = trace->tb_frame;
+        Py_XINCREF(frame);
         errorString += "\n\nAt:\n";
         while (frame) {
-#    if PY_VERSION_HEX >= 0x03090000
+#    if PY_VERSION_HEX >= 0x030900B1
             PyCodeObject *f_code = PyFrame_GetCode(frame);
 #    else
             PyCodeObject *f_code = frame->f_code;
@@ -514,8 +515,15 @@ PYBIND11_NOINLINE std::string error_string() {
             errorString += "  " + handle(f_code->co_filename).cast<std::string>() + "("
                            + std::to_string(lineno)
                            + "): " + handle(f_code->co_name).cast<std::string>() + "\n";
-            frame = frame->f_back;
             Py_DECREF(f_code);
+#    if PY_VERSION_HEX >= 0x030900B1
+            auto *b_frame = PyFrame_GetBack(frame);
+#    else
+            auto *b_frame = frame->f_back;
+            Py_XINCREF(b_frame);
+#    endif
+            Py_DECREF(frame);
+            frame = b_frame;
         }
     }
 #endif
diff --git a/include/pybind11/pybind11.h b/include/pybind11/pybind11.h
index 1ec6c17c6..4f6b2cdf4 100644
--- a/include/pybind11/pybind11.h
+++ b/include/pybind11/pybind11.h
@@ -2636,9 +2636,7 @@ get_type_override(const void *this_ptr, const type_info *this_type, const char *
 
     /* Don't call dispatch code if invoked from overridden function.
        Unfortunately this doesn't work on PyPy. */
-#if !defined(PYPY_VERSION) && PY_VERSION_HEX < 0x030B0000
-    // TODO: Remove PyPy workaround for Python 3.11.
-    // Current API fails on 3.11 since co_varnames can be null.
+#if !defined(PYPY_VERSION)
 #    if PY_VERSION_HEX >= 0x03090000
     PyFrameObject *frame = PyThreadState_GetFrame(PyThreadState_Get());
     if (frame != nullptr) {
@@ -2646,9 +2644,11 @@ get_type_override(const void *this_ptr, const type_info *this_type, const char *
         // f_code is guaranteed to not be NULL
         if ((std::string) str(f_code->co_name) == name && f_code->co_argcount > 0) {
             PyObject *locals = PyEval_GetLocals();
-            if (locals != nullptr && f_code->co_varnames != nullptr) {
-                PyObject *self_caller
-                    = dict_getitem(locals, PyTuple_GET_ITEM(f_code->co_varnames, 0));
+            if (locals != nullptr) {
+                PyObject *co_varnames = PyObject_GetAttrString((PyObject *) f_code, "co_varnames");
+                PyObject *self_arg = PyTuple_GET_ITEM(co_varnames, 0);
+                Py_DECREF(co_varnames);
+                PyObject *self_caller = dict_getitem(locals, self_arg);
                 if (self_caller == self.ptr()) {
                     Py_DECREF(f_code);
                     Py_DECREF(frame);