diff --git a/Misc/NEWS b/Misc/NEWS
index 20cf656..8bd0dd3 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -10,6 +10,8 @@
 Core and Builtins
 -----------------
 
+- Issue #20437: Fixed 22 potential bugs when deleting objects references.
+
 - Issue #20500: Displaying an exception at interpreter shutdown no longer
   risks triggering an assertion failure in PyObject_Str.
 
diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
index 820a606..97ae798 100644
--- a/Modules/_ctypes/_ctypes.c
+++ b/Modules/_ctypes/_ctypes.c
@@ -159,10 +159,8 @@
         if (-1 == PyDict_DelItem(self->dict, self->key))
             /* XXX Error context */
             PyErr_WriteUnraisable(Py_None);
-        Py_DECREF(self->key);
-        self->key = NULL;
-        Py_DECREF(self->dict);
-        self->dict = NULL;
+        Py_CLEAR(self->key);
+        Py_CLEAR(self->dict);
     }
     Py_INCREF(Py_None);
     return Py_None;
@@ -2934,10 +2932,8 @@
 PyCFuncPtr_set_restype(PyCFuncPtrObject *self, PyObject *ob)
 {
     if (ob == NULL) {
-        Py_XDECREF(self->restype);
-        self->restype = NULL;
-        Py_XDECREF(self->checker);
-        self->checker = NULL;
+        Py_CLEAR(self->restype);
+        Py_CLEAR(self->checker);
         return 0;
     }
     if (ob != Py_None && !PyType_stgdict(ob) && !PyCallable_Check(ob)) {
@@ -2980,10 +2976,8 @@
     PyObject *converters;
 
     if (ob == NULL || ob == Py_None) {
-        Py_XDECREF(self->converters);
-        self->converters = NULL;
-        Py_XDECREF(self->argtypes);
-        self->argtypes = NULL;
+        Py_CLEAR(self->converters);
+        Py_CLEAR(self->argtypes);
     } else {
         converters = converters_from_argtypes(ob);
         if (!converters)
diff --git a/Modules/_sqlite/cursor.c b/Modules/_sqlite/cursor.c
index 8d10890..ce92af6 100644
--- a/Modules/_sqlite/cursor.c
+++ b/Modules/_sqlite/cursor.c
@@ -229,8 +229,7 @@
             if (converter != Py_None) {
                 Py_DECREF(converter);
             }
-            Py_XDECREF(self->row_cast_map);
-            self->row_cast_map = NULL;
+            Py_CLEAR(self->row_cast_map);
 
             return -1;
         }
@@ -447,8 +446,7 @@
     self->locked = 1;
     self->reset = 0;
 
-    Py_XDECREF(self->next_row);
-    self->next_row = NULL;
+    Py_CLEAR(self->next_row);
 
     if (multiple) {
         /* executemany() */
@@ -864,8 +862,7 @@
     if (!self->next_row) {
          if (self->statement) {
             (void)pysqlite_statement_reset(self->statement);
-            Py_DECREF(self->statement);
-            self->statement = NULL;
+            Py_CLEAR(self->statement);
         }
         return NULL;
     }
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 1428220..60d0099 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -780,8 +780,7 @@
 static void
 path_cleanup(path_t *path) {
     if (path->cleanup) {
-        Py_DECREF(path->cleanup);
-        path->cleanup = NULL;
+        Py_CLEAR(path->cleanup);
     }
 }
 
diff --git a/Modules/pyexpat.c b/Modules/pyexpat.c
index 3f51c12..a71ecc5 100644
--- a/Modules/pyexpat.c
+++ b/Modules/pyexpat.c
@@ -317,8 +317,7 @@
     }
     else {
         if (trace_frame(tstate, f, PyTrace_RETURN, res) < 0) {
-            Py_XDECREF(res);
-            res = NULL;
+            Py_CLEAR(res);
         }
     }
 #else
diff --git a/Modules/readline.c b/Modules/readline.c
index 0be39da..4bba0db 100644
--- a/Modules/readline.c
+++ b/Modules/readline.c
@@ -281,8 +281,7 @@
     if (!PyArg_ParseTuple(args, buf, &function))
         return NULL;
     if (function == Py_None) {
-        Py_XDECREF(*hook_var);
-        *hook_var = NULL;
+        Py_CLEAR(*hook_var);
     }
     else if (PyCallable_Check(function)) {
         PyObject *tmp = *hook_var;
@@ -885,7 +884,7 @@
         (r != Py_None && PyLong_AsLong(r) == -1 && PyErr_Occurred())) {
         goto error;
     }
-    Py_XDECREF(r); r=NULL;
+    Py_CLEAR(r);
 
     if (0) {
     error:
diff --git a/Modules/selectmodule.c b/Modules/selectmodule.c
index 0c9b9d9..0b11a01 100644
--- a/Modules/selectmodule.c
+++ b/Modules/selectmodule.c
@@ -66,8 +66,7 @@
 {
     int i;
     for (i = 0; i < FD_SETSIZE + 1 && fd2obj[i].sentinel >= 0; i++) {
-        Py_XDECREF(fd2obj[i].obj);
-        fd2obj[i].obj = NULL;
+        Py_CLEAR(fd2obj[i].obj);
     }
     fd2obj[0].sentinel = -1;
 }
diff --git a/Modules/signalmodule.c b/Modules/signalmodule.c
index 9a0e8e3..43e3ca1 100644
--- a/Modules/signalmodule.c
+++ b/Modules/signalmodule.c
@@ -1305,12 +1305,9 @@
         Py_XDECREF(func);
     }
 
-    Py_XDECREF(IntHandler);
-    IntHandler = NULL;
-    Py_XDECREF(DefaultHandler);
-    DefaultHandler = NULL;
-    Py_XDECREF(IgnoreHandler);
-    IgnoreHandler = NULL;
+    Py_CLEAR(IntHandler);
+    Py_CLEAR(DefaultHandler);
+    Py_CLEAR(IgnoreHandler);
 }
 
 
diff --git a/Modules/syslogmodule.c b/Modules/syslogmodule.c
index 9d79eec..f2d44ff 100644
--- a/Modules/syslogmodule.c
+++ b/Modules/syslogmodule.c
@@ -197,8 +197,7 @@
 {
     if (S_log_open) {
         closelog();
-        Py_XDECREF(S_ident_o);
-        S_ident_o = NULL;
+        Py_CLEAR(S_ident_o);
         S_log_open = 0;
     }
     Py_INCREF(Py_None);
diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index 2ba264f..52744b9 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -463,8 +463,7 @@
     }
 
  error:
-    Py_XDECREF(self);
-    self = NULL;
+    Py_CLEAR(self);
  success:
     return (PyObject*)self;
 }
diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c
index 5625a65..c63afcc 100644
--- a/Objects/tupleobject.c
+++ b/Objects/tupleobject.c
@@ -879,8 +879,7 @@
     _Py_ForgetReference((PyObject *) v);
     /* DECREF items deleted by shrinkage */
     for (i = newsize; i < oldsize; i++) {
-        Py_XDECREF(v->ob_item[i]);
-        v->ob_item[i] = NULL;
+        Py_CLEAR(v->ob_item[i]);
     }
     sv = PyObject_GC_Resize(PyTupleObject, v, newsize);
     if (sv == NULL) {
@@ -926,8 +925,7 @@
 #if PyTuple_MAXSAVESIZE > 0
     /* empty tuples are used all over the place and applications may
      * rely on the fact that an empty tuple is a singleton. */
-    Py_XDECREF(free_list[0]);
-    free_list[0] = NULL;
+    Py_CLEAR(free_list[0]);
 
     (void)PyTuple_ClearFreeList();
 #endif
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index eae4bc5..994c4f5 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -1902,8 +1902,7 @@
 {
     _Py_Identifier *tmp, *s = static_strings;
     while (s) {
-        Py_DECREF(s->object);
-        s->object = NULL;
+        Py_CLEAR(s->object);
         tmp = s->next;
         s->next = NULL;
         s = tmp;
@@ -4005,8 +4004,7 @@
     return;
 
 onError:
-    Py_DECREF(*exceptionObject);
-    *exceptionObject = NULL;
+    Py_CLEAR(*exceptionObject);
 }
 
 #ifdef HAVE_MBCS
@@ -6366,8 +6364,7 @@
             goto onError;
         return;
       onError:
-        Py_DECREF(*exceptionObject);
-        *exceptionObject = NULL;
+        Py_CLEAR(*exceptionObject);
     }
 }
 
@@ -8410,8 +8407,7 @@
             goto onError;
         return;
       onError:
-        Py_DECREF(*exceptionObject);
-        *exceptionObject = NULL;
+        Py_CLEAR(*exceptionObject);
     }
 }
 
@@ -13502,8 +13498,7 @@
         PyObject *newbuffer;
         newbuffer = resize_compact(writer->buffer, writer->pos);
         if (newbuffer == NULL) {
-            Py_DECREF(writer->buffer);
-            writer->buffer = NULL;
+            Py_CLEAR(writer->buffer);
             return NULL;
         }
         writer->buffer = newbuffer;
diff --git a/Python/ceval.c b/Python/ceval.c
index 34c52b0..5db88be 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -3189,8 +3189,7 @@
                 if (call_trace(tstate->c_tracefunc, tstate->c_traceobj,
                                tstate, f,
                                PyTrace_RETURN, retval)) {
-                    Py_XDECREF(retval);
-                    retval = NULL;
+                    Py_CLEAR(retval);
                     why = WHY_EXCEPTION;
                 }
             }
@@ -3209,8 +3208,7 @@
             else if (call_trace(tstate->c_profilefunc, tstate->c_profileobj,
                                 tstate, f,
                                 PyTrace_RETURN, retval)) {
-                Py_XDECREF(retval);
-                retval = NULL;
+                Py_CLEAR(retval);
                 /* why = WHY_EXCEPTION; */
             }
         }
@@ -3568,8 +3566,7 @@
     if (co->co_flags & CO_GENERATOR) {
         /* Don't need to keep the reference to f_back, it will be set
          * when the generator is resumed. */
-        Py_XDECREF(f->f_back);
-        f->f_back = NULL;
+        Py_CLEAR(f->f_back);
 
         PCALL(PCALL_GENERATOR);
 
diff --git a/Python/import.c b/Python/import.c
index 001d745..d0115e4 100644
--- a/Python/import.c
+++ b/Python/import.c
@@ -349,8 +349,7 @@
 void
 _PyImport_Fini(void)
 {
-    Py_XDECREF(extensions);
-    extensions = NULL;
+    Py_CLEAR(extensions);
 #ifdef WITH_THREAD
     if (import_lock != NULL) {
         PyThread_free_lock(import_lock);
@@ -598,8 +597,7 @@
             /* Somebody already imported the module,
                likely under a different name.
                XXX this should really not happen. */
-            Py_DECREF(def->m_base.m_copy);
-            def->m_base.m_copy = NULL;
+            Py_CLEAR(def->m_base.m_copy);
         }
         dict = PyModule_GetDict(mod);
         if (dict == NULL)
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index 976d5a0..9ec3bfa 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -430,8 +430,7 @@
     result = call_trampoline(callback, frame, what, arg);
     if (result == NULL) {
         PyEval_SetTrace(NULL, NULL);
-        Py_XDECREF(frame->f_trace);
-        frame->f_trace = NULL;
+        Py_CLEAR(frame->f_trace);
         return -1;
     }
     if (result != Py_None) {