diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst
index 22e7458013fb3db..a951dd575ad2425 100644
--- a/Doc/c-api/object.rst
+++ b/Doc/c-api/object.rst
@@ -85,9 +85,9 @@ Object Protocol
    return ``0`` on success.  This is the equivalent of the Python statement
    ``o.attr_name = v``.
 
-   If *v* is ``NULL``, the attribute is deleted. This behaviour is deprecated
-   in favour of using :c:func:`PyObject_DelAttr`, but there are currently no
-   plans to remove it.
+   .. deprecated:: 3.13
+      Calling ``PyObject_SetAttrString(o, attr_name, NULL)`` is deprecated:
+      ``PyObject_DelAttr(o, attr_name)`` must be used instead.
 
 
 .. c:function:: int PyObject_SetAttrString(PyObject *o, const char *attr_name, PyObject *v)
@@ -97,8 +97,9 @@ Object Protocol
    return ``0`` on success.  This is the equivalent of the Python statement
    ``o.attr_name = v``.
 
-   If *v* is ``NULL``, the attribute is deleted, but this feature is
-   deprecated in favour of using :c:func:`PyObject_DelAttrString`.
+   .. deprecated:: 3.13
+      Calling ``PyObject_SetAttrString(o, attr_name, NULL)`` is deprecated:
+      ``PyObject_DelAttrString(o, attr_name)`` must be used instead.
 
 
 .. c:function:: int PyObject_GenericSetAttr(PyObject *o, PyObject *name, PyObject *value)
diff --git a/Doc/data/stable_abi.dat b/Doc/data/stable_abi.dat
index 7fb002cd80369b6..9a61ddc39a353fd 100644
--- a/Doc/data/stable_abi.dat
+++ b/Doc/data/stable_abi.dat
@@ -490,6 +490,8 @@ function,PyObject_Calloc,3.7,,
 function,PyObject_CheckBuffer,3.11,,
 function,PyObject_ClearWeakRefs,3.2,,
 function,PyObject_CopyData,3.11,,
+function,PyObject_DelAttr,3.13,,
+function,PyObject_DelAttrString,3.13,,
 function,PyObject_DelItem,3.2,,
 function,PyObject_DelItemString,3.2,,
 function,PyObject_Dir,3.2,,
diff --git a/Doc/whatsnew/3.13.rst b/Doc/whatsnew/3.13.rst
index 8fc809deca139b3..7cfa1c4b2690865 100644
--- a/Doc/whatsnew/3.13.rst
+++ b/Doc/whatsnew/3.13.rst
@@ -779,6 +779,14 @@ Deprecated
   :c:func:`PyWeakref_GetRef` on Python 3.12 and older.
   (Contributed by Victor Stinner in :gh:`105927`.)
 
+* Deprecate ``PyObject_SetAttr(v, name, NULL)`` and
+  ``PyObject_SetAttrString(v, name, NULL)``: use ``PyObject_DelAttr(v, name)``
+  and ``PyObject_DelAttrString(v, name)`` instead. When
+  :c:func:`PyObject_SetAttr` is called with a ``NULL`` value, it's unclear if
+  the caller wants to remove the attribute on purpose, or if the value is
+  ``NULL`` because of an error. Such API is error prone and should be avoided.
+  (Contributed by Victor Stinner in :gh:`106572`.)
+
 Removed
 -------
 
diff --git a/Include/abstract.h b/Include/abstract.h
index 016ace9bc89e964..c84d2c704e96051 100644
--- a/Include/abstract.h
+++ b/Include/abstract.h
@@ -80,7 +80,7 @@ extern "C" {
 
    This is the equivalent of the Python statement o.attr_name=v. */
 
-/* Implemented as a macro:
+/* Implemented elsewhere:
 
    int PyObject_DelAttrString(PyObject *o, const char *attr_name);
 
@@ -88,17 +88,15 @@ extern "C" {
    -1 on failure.
 
    This is the equivalent of the Python statement: del o.attr_name. */
-#define PyObject_DelAttrString(O, A) PyObject_SetAttrString((O), (A), NULL)
 
 
-/* Implemented as a macro:
+/* Implemented elsewhere:
 
    int PyObject_DelAttr(PyObject *o, PyObject *attr_name);
 
    Delete attribute named attr_name, for object o. Returns -1
    on failure.  This is the equivalent of the Python
    statement: del o.attr_name. */
-#define  PyObject_DelAttr(O, A) PyObject_SetAttr((O), (A), NULL)
 
 
 /* Implemented elsewhere:
diff --git a/Include/object.h b/Include/object.h
index 3ef64511399c66f..dccab07e5f2c6fe 100644
--- a/Include/object.h
+++ b/Include/object.h
@@ -391,9 +391,11 @@ PyAPI_FUNC(PyObject *) PyObject_RichCompare(PyObject *, PyObject *, int);
 PyAPI_FUNC(int) PyObject_RichCompareBool(PyObject *, PyObject *, int);
 PyAPI_FUNC(PyObject *) PyObject_GetAttrString(PyObject *, const char *);
 PyAPI_FUNC(int) PyObject_SetAttrString(PyObject *, const char *, PyObject *);
+PyAPI_FUNC(int) PyObject_DelAttrString(PyObject *v, const char *name);
 PyAPI_FUNC(int) PyObject_HasAttrString(PyObject *, const char *);
 PyAPI_FUNC(PyObject *) PyObject_GetAttr(PyObject *, PyObject *);
 PyAPI_FUNC(int) PyObject_SetAttr(PyObject *, PyObject *, PyObject *);
+PyAPI_FUNC(int) PyObject_DelAttr(PyObject *v, PyObject *name);
 PyAPI_FUNC(int) PyObject_HasAttr(PyObject *, PyObject *);
 PyAPI_FUNC(PyObject *) PyObject_SelfIter(PyObject *);
 PyAPI_FUNC(PyObject *) PyObject_GenericGetAttr(PyObject *, PyObject *);
diff --git a/Lib/test/test_stable_abi_ctypes.py b/Lib/test/test_stable_abi_ctypes.py
index 038c978e7bbd02b..20bc2624c813611 100644
--- a/Lib/test/test_stable_abi_ctypes.py
+++ b/Lib/test/test_stable_abi_ctypes.py
@@ -509,6 +509,8 @@ def test_windows_feature_macros(self):
     "PyObject_CheckReadBuffer",
     "PyObject_ClearWeakRefs",
     "PyObject_CopyData",
+    "PyObject_DelAttr",
+    "PyObject_DelAttrString",
     "PyObject_DelItem",
     "PyObject_DelItemString",
     "PyObject_Dir",
diff --git a/Misc/NEWS.d/next/C API/2023-07-10-13-39-56.gh-issue-106572.3ZQjCa.rst b/Misc/NEWS.d/next/C API/2023-07-10-13-39-56.gh-issue-106572.3ZQjCa.rst
new file mode 100644
index 000000000000000..eea855d9dee4647
--- /dev/null
+++ b/Misc/NEWS.d/next/C API/2023-07-10-13-39-56.gh-issue-106572.3ZQjCa.rst	
@@ -0,0 +1,7 @@
+Deprecate ``PyObject_SetAttr(v, name, NULL)`` and
+``PyObject_SetAttrString(v, name, NULL)``: use ``PyObject_DelAttr(v, name)``
+and ``PyObject_DelAttrString(v, name)`` instead. When
+:c:func:`PyObject_SetAttr` is called with a ``NULL`` value, it's unclear if the
+caller wants to remove the attribute on purpose, or if the value is ``NULL``
+because of an error. Such API is error prone and should be avoided. Patch by
+Victor Stinner.
diff --git a/Misc/stable_abi.toml b/Misc/stable_abi.toml
index bc7259f11816f3d..c61fedf8390e283 100644
--- a/Misc/stable_abi.toml
+++ b/Misc/stable_abi.toml
@@ -2432,3 +2432,7 @@
     added = '3.13'
 [function.PyWeakref_GetRef]
     added = '3.13'
+[function.PyObject_DelAttr]
+    added = '3.13'
+[function.PyObject_DelAttrString]
+    added = '3.13'
diff --git a/Objects/object.c b/Objects/object.c
index c27b13e9e0c31ac..b07baeee83ae1c9 100644
--- a/Objects/object.c
+++ b/Objects/object.c
@@ -926,8 +926,8 @@ PyObject_HasAttrString(PyObject *v, const char *name)
     return ok;
 }
 
-int
-PyObject_SetAttrString(PyObject *v, const char *name, PyObject *w)
+static int
+object_set_attr_string(PyObject *v, const char *name, PyObject *w)
 {
     PyObject *s;
     int res;
@@ -942,6 +942,26 @@ PyObject_SetAttrString(PyObject *v, const char *name, PyObject *w)
     return res;
 }
 
+int
+PyObject_SetAttrString(PyObject *v, const char *name, PyObject *w)
+{
+    if (w == NULL
+        && PyErr_WarnEx(PyExc_DeprecationWarning,
+                        "PyObject_SetAttrString(v, name, NULL) is deprecated: "
+                        "use PyObject_DelAttrString(v, name) instead",
+                        1) < 0)
+    {
+        return -1;
+    }
+    return object_set_attr_string(v, name, w);
+}
+
+int
+PyObject_DelAttrString(PyObject *v, const char *name)
+{
+    return object_set_attr_string(v, name, NULL);
+}
+
 int
 _PyObject_IsAbstract(PyObject *obj)
 {
@@ -1136,8 +1156,8 @@ PyObject_HasAttr(PyObject *v, PyObject *name)
     return 1;
 }
 
-int
-PyObject_SetAttr(PyObject *v, PyObject *name, PyObject *value)
+static int
+object_set_attr(PyObject *v, PyObject *name, PyObject *value)
 {
     PyTypeObject *tp = Py_TYPE(v);
     int err;
@@ -1185,6 +1205,26 @@ PyObject_SetAttr(PyObject *v, PyObject *name, PyObject *value)
     return -1;
 }
 
+int
+PyObject_SetAttr(PyObject *v, PyObject *name, PyObject *value)
+{
+    if (value == NULL
+        && PyErr_WarnEx(PyExc_DeprecationWarning,
+                        "PyObject_SetAttr(v, name, NULL) is deprecated: "
+                        "use PyObject_DelAttr(v, name) instead",
+                        1) < 0)
+    {
+        return -1;
+    }
+    return object_set_attr(v, name, value);
+}
+
+int
+PyObject_DelAttr(PyObject *v, PyObject *name)
+{
+    return object_set_attr(v, name, NULL);
+}
+
 PyObject **
 _PyObject_ComputedDictPointer(PyObject *obj)
 {
diff --git a/Objects/weakrefobject.c b/Objects/weakrefobject.c
index e9563729bf82ba6..913564ed9379f61 100644
--- a/Objects/weakrefobject.c
+++ b/Objects/weakrefobject.c
@@ -485,7 +485,13 @@ proxy_setattr(PyObject *proxy, PyObject *name, PyObject *value)
     if (!proxy_check_ref(obj)) {
         return -1;
     }
-    int res = PyObject_SetAttr(obj, name, value);
+    int res;
+    if (value != NULL) {
+        res = PyObject_SetAttr(obj, name, value);
+    }
+    else {
+        res = PyObject_DelAttr(obj, name);
+    }
     Py_DECREF(obj);
     return res;
 }
diff --git a/PC/python3dll.c b/PC/python3dll.c
index 65bdf326ffbc7f0..a7173911c7c1e84 100755
--- a/PC/python3dll.c
+++ b/PC/python3dll.c
@@ -447,6 +447,8 @@ EXPORT_FUNC(PyObject_CheckBuffer)
 EXPORT_FUNC(PyObject_CheckReadBuffer)
 EXPORT_FUNC(PyObject_ClearWeakRefs)
 EXPORT_FUNC(PyObject_CopyData)
+EXPORT_FUNC(PyObject_DelAttr)
+EXPORT_FUNC(PyObject_DelAttrString)
 EXPORT_FUNC(PyObject_DelItem)
 EXPORT_FUNC(PyObject_DelItemString)
 EXPORT_FUNC(PyObject_Dir)
diff --git a/Python/bltinmodule.c b/Python/bltinmodule.c
index 49efafc07f4245f..20a86fc6f583d3d 100644
--- a/Python/bltinmodule.c
+++ b/Python/bltinmodule.c
@@ -1567,8 +1567,9 @@ static PyObject *
 builtin_delattr_impl(PyObject *module, PyObject *obj, PyObject *name)
 /*[clinic end generated code: output=85134bc58dff79fa input=164865623abe7216]*/
 {
-    if (PyObject_SetAttr(obj, name, (PyObject *)NULL) != 0)
+    if (PyObject_DelAttr(obj, name) < 0) {
         return NULL;
+    }
     Py_RETURN_NONE;
 }
 
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index 0848bbfd203ec49..88444293aa228b9 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -1240,7 +1240,7 @@ dummy_func(
 
         inst(DELETE_ATTR, (owner --)) {
             PyObject *name = GETITEM(FRAME_CO_NAMES, oparg);
-            int err = PyObject_SetAttr(owner, name, (PyObject *)NULL);
+            int err = PyObject_DelAttr(owner, name);
             DECREF_INPUTS();
             ERROR_IF(err, error);
         }
diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index 0ef752249ccb762..facaef83e64fa20 100644
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -1018,7 +1018,7 @@
             PyObject *owner = stack_pointer[-1];
             #line 1242 "Python/bytecodes.c"
             PyObject *name = GETITEM(FRAME_CO_NAMES, oparg);
-            int err = PyObject_SetAttr(owner, name, (PyObject *)NULL);
+            int err = PyObject_DelAttr(owner, name);
             #line 1023 "Python/executor_cases.c.h"
             Py_DECREF(owner);
             #line 1245 "Python/bytecodes.c"
diff --git a/Python/generated_cases.c.h b/Python/generated_cases.c.h
index 11823cf9cd293c0..ecbf8ee59da1da1 100644
--- a/Python/generated_cases.c.h
+++ b/Python/generated_cases.c.h
@@ -1696,7 +1696,7 @@
             PyObject *owner = stack_pointer[-1];
             #line 1242 "Python/bytecodes.c"
             PyObject *name = GETITEM(FRAME_CO_NAMES, oparg);
-            int err = PyObject_SetAttr(owner, name, (PyObject *)NULL);
+            int err = PyObject_DelAttr(owner, name);
             #line 1701 "Python/generated_cases.c.h"
             Py_DECREF(owner);
             #line 1245 "Python/bytecodes.c"