diff --git a/Doc/c-api/frame.rst b/Doc/c-api/frame.rst
index 68e5dc6daeae..46ce700abf14 100644
--- a/Doc/c-api/frame.rst
+++ b/Doc/c-api/frame.rst
@@ -27,8 +27,6 @@ See also :ref:`Reflection <reflection>`.
    Return a :term:`strong reference`, or ``NULL`` if *frame* has no outer
    frame.
 
-   *frame* must not be ``NULL``.
-
    .. versionadded:: 3.9
 
 
@@ -38,8 +36,6 @@ See also :ref:`Reflection <reflection>`.
 
    Return a :term:`strong reference`. The result cannot be ``NULL``.
 
-   *frame* must not be ``NULL``.
-
    .. versionadded:: 3.11
 
 
@@ -49,7 +45,7 @@ See also :ref:`Reflection <reflection>`.
 
    Return a :term:`strong reference`.
 
-   *frame* must not be ``NULL``. The result (frame code) cannot be ``NULL``.
+   The result (frame code) cannot be ``NULL``.
 
    .. versionadded:: 3.9
 
@@ -62,8 +58,6 @@ See also :ref:`Reflection <reflection>`.
 
    Return a :term:`strong reference`, or ``NULL``.
 
-   *frame* must not be ``NULL``.
-
    .. versionadded:: 3.11
 
 
@@ -73,19 +67,15 @@ See also :ref:`Reflection <reflection>`.
 
    Return a :term:`strong reference`. The result cannot be ``NULL``.
 
-   *frame* must not be ``NULL``.
-
    .. versionadded:: 3.11
 
 
 .. c:function:: int PyFrame_GetLasti(PyFrameObject *frame)
 
-   Get the *frame*'s ``f_lasti`` attribute (:class:`dict`).
+   Get the *frame*'s ``f_lasti`` attribute.
 
    Returns -1 if ``frame.f_lasti`` is ``None``.
 
-   *frame* must not be ``NULL``.
-
    .. versionadded:: 3.11
 
 
@@ -95,13 +85,9 @@ See also :ref:`Reflection <reflection>`.
 
    Return a :term:`strong reference`.
 
-   *frame* must not be ``NULL``.
-
    .. versionadded:: 3.11
 
 
 .. c:function:: int PyFrame_GetLineNumber(PyFrameObject *frame)
 
    Return the line number that *frame* is currently executing.
-
-   *frame* must not be ``NULL``.
diff --git a/Misc/NEWS.d/next/C API/2022-04-08-11-29-36.bpo-40421.H0ORmT.rst b/Misc/NEWS.d/next/C API/2022-04-08-11-29-36.bpo-40421.H0ORmT.rst
index 2e10c2394c93..d4a1dbecf286 100644
--- a/Misc/NEWS.d/next/C API/2022-04-08-11-29-36.bpo-40421.H0ORmT.rst	
+++ b/Misc/NEWS.d/next/C API/2022-04-08-11-29-36.bpo-40421.H0ORmT.rst	
@@ -1,2 +1,2 @@
-Add ``PyFrame_GetLasti`` C-API function to access frame object's ``lasti``
+Add ``PyFrame_GetLasti`` C-API function to access frame object's ``f_lasti``
 attribute safely from C code.
diff --git a/Objects/frameobject.c b/Objects/frameobject.c
index dc4ef8bcda54..e65395ee5f20 100644
--- a/Objects/frameobject.c
+++ b/Objects/frameobject.c
@@ -1160,7 +1160,7 @@ PyFrame_GetLasti(PyFrameObject *frame)
     if (lasti < 0) {
         return -1;
     }
-    return lasti*2;
+    return lasti * sizeof(_Py_CODEUNIT);
 }
 
 PyObject *