diff --git a/src/sage/matrix/args.pxd b/src/sage/matrix/args.pxd
index ba26cfbafbe..5f29dac712d 100644
--- a/src/sage/matrix/args.pxd
+++ b/src/sage/matrix/args.pxd
@@ -1,4 +1,5 @@
 from cpython.object cimport PyObject
+from cpython.ref cimport _Py_REFCNT
 from sage.structure.element cimport Element, Matrix
 from sage.structure.parent cimport Parent
 
@@ -64,7 +65,7 @@ cdef class MatrixArgs:
         Can we safely return self.entries without making a copy?
         A refcount of 1 means that self.entries is the only reference.
         """
-        return (<PyObject*>self.entries).ob_refcnt == 1
+        return _Py_REFCNT(<PyObject*>self.entries) == 1
 
     cdef inline bint need_to_convert(self, x) noexcept:
         """Is ``x`` not an element of ``self.base``?"""
diff --git a/src/sage/rings/integer.pyx b/src/sage/rings/integer.pyx
index bdd2a7ce05b..3a9e238b6c9 100644
--- a/src/sage/rings/integer.pyx
+++ b/src/sage/rings/integer.pyx
@@ -207,6 +207,9 @@ new_gen_from_integer = None
 cdef extern from *:
     int unlikely(int) nogil  # Defined by Cython
 
+cdef extern from "Python.h":
+    void Py_SET_REFCNT(PyObject*, Py_ssize_t) nogil
+
 cdef object numpy_long_interface = {'typestr': '=i4' if sizeof(long) == 4 else '=i8'}
 cdef object numpy_int64_interface = {'typestr': '=i8'}
 cdef object numpy_object_interface = {'typestr': '|O'}
@@ -7724,7 +7727,7 @@ cdef PyObject* fast_tp_new(type t, args, kwds) except NULL:
     # Objects from the pool have reference count zero, so this
     # needs to be set in this case.
 
-    new.ob_refcnt = 1
+    Py_SET_REFCNT(<PyObject*>new, 1)
 
     return new
 
diff --git a/src/sage/rings/real_double.pyx b/src/sage/rings/real_double.pyx
index cac66b4ac75..543802dbba0 100644
--- a/src/sage/rings/real_double.pyx
+++ b/src/sage/rings/real_double.pyx
@@ -45,6 +45,9 @@ from libc.string cimport memcpy
 from cpython.object cimport *
 from cpython.float cimport *
 
+cdef extern from "Python.h":
+    void Py_SET_REFCNT(PyObject*, Py_ssize_t) nogil
+
 from sage.ext.stdsage cimport PY_NEW
 from sage.cpython.python_debug cimport if_Py_TRACE_REFS_then_PyObject_INIT
 
@@ -2157,7 +2160,7 @@ cdef PyObject* fast_tp_new(type t, args, kwds) noexcept:
     # Objects from the pool have reference count zero, so this
     # needs to be set in this case.
 
-    new.ob_refcnt = 1
+    Py_SET_REFCNT(<PyObject*>new, 1)
 
     return new
 
diff --git a/src/sage/symbolic/ginac/numeric.cpp b/src/sage/symbolic/ginac/numeric.cpp
index bcb470f911b..6b1c2524a86 100644
--- a/src/sage/symbolic/ginac/numeric.cpp
+++ b/src/sage/symbolic/ginac/numeric.cpp
@@ -81,14 +81,14 @@
 
 #define Py_INCREF(op) (                         \
     _Py_INC_REFTOTAL  _Py_REF_DEBUG_COMMA       \
-    ((PyObject*)(op))->ob_refcnt++) ; \
+    Py_SET_REFCNT((PyObject*)(op), Py_REFCNT(op) + 1)) ; \
 std::cerr << "+ " << long(op) << ", " << Py_REFCNT(op) << ", " << Py_TYPE(op)->tp_name << std::endl; std::cerr.flush();
 
 #define Py_DECREF(op)                                   \
     do {                                                \
 std::cerr << "- " << long(op) << ", " << Py_REFCNT(op) << ", " << Py_TYPE(op)->tp_name << std::endl; std::cerr.flush(); \
         if (_Py_DEC_REFTOTAL  _Py_REF_DEBUG_COMMA       \
-        --((PyObject*)(op))->ob_refcnt != 0)            \
+        (Py_SET_REFCNT((PyObject*)(op), Py_REFCNT(op) - 1), Py_REFCNT(op) != 0))            \
             _Py_CHECK_REFCNT(op)                        \
         else                                            \
         _Py_Dealloc((PyObject *)(op));                  \