diff --git a/Doc/library/curses.rst b/Doc/library/curses.rst
index 1201e8972d..50a59b1893 100644
--- a/Doc/library/curses.rst
+++ b/Doc/library/curses.rst
@@ -516,6 +516,7 @@ The module :mod:`curses` defines the following functions:
    Retrieves the value set by :func:`set_escdelay`.
 
    .. versionadded:: 3.9
+   .. availability:: not available with stock AIX
 
 .. function:: set_escdelay(ms)
 
@@ -524,12 +525,14 @@ The module :mod:`curses` defines the following functions:
    keyboard from escape sequences sent by cursor and function keys.
 
    .. versionadded:: 3.9
+   .. availability:: not available with stock AIX
 
 .. function:: get_tabsize()
 
    Retrieves the value set by :func:`set_tabsize`.
 
    .. versionadded:: 3.9
+   .. availability:: not available with stock AIX
 
 .. function:: set_tabsize(size)
 
@@ -537,6 +540,7 @@ The module :mod:`curses` defines the following functions:
    character to spaces as it adds the tab to a window.
 
    .. versionadded:: 3.9
+   .. availability:: not available with stock AIX
 
 .. function:: setsyx(y, x)
 
diff --git a/Lib/test/test_curses.py b/Lib/test/test_curses.py
index 5e619d1383..d50d2853ec 100644
--- a/Lib/test/test_curses.py
+++ b/Lib/test/test_curses.py
@@ -261,10 +261,11 @@ class TestCurses(unittest.TestCase):
         curses.putp(b'abc')
         curses.qiflush()
         curses.raw() ; curses.raw(1)
-        curses.set_escdelay(25)
-        self.assertEqual(curses.get_escdelay(), 25)
-        curses.set_tabsize(4)
-        self.assertEqual(curses.get_tabsize(), 4)
+        if hasattr(curses, 'set_escdalay'):
+            curses.set_escdelay(25)
+            self.assertEqual(curses.get_escdelay(), 25)
+            curses.set_tabsize(4)
+            self.assertEqual(curses.get_tabsize(), 4)
         if hasattr(curses, 'setsyx'):
             curses.setsyx(5,5)
         curses.tigetflag('hc')
diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
index c2ce3a968f..e65f50adab 100644
--- a/Modules/_cursesmodule.c
+++ b/Modules/_cursesmodule.c
@@ -3255,6 +3255,10 @@ _curses_setupterm_impl(PyObject *module, const char *term, int fd)
     Py_RETURN_NONE;
 }
 
+#if !defined(_AIX) || defined(NCURSES_VERSION)
+/* bpo-39020 - stock AIX curses does not include ESCDELAY
+ * a third-party addtion of (gnu) ncurses might
+ */
 /*[clinic input]
 _curses.get_escdelay
 
@@ -3334,6 +3338,7 @@ _curses_set_tabsize_impl(PyObject *module, int size)
 
     return PyCursesCheckERR(set_tabsize(size), "set_tabsize");
 }
+#endif
 
 /*[clinic input]
 _curses.intrflush
diff --git a/Modules/clinic/_cursesmodule.c.h b/Modules/clinic/_cursesmodule.c.h
index f3780f8e01..a9031781f9 100644
--- a/Modules/clinic/_cursesmodule.c.h
+++ b/Modules/clinic/_cursesmodule.c.h
@@ -3040,6 +3040,10 @@ exit:
     return return_value;
 }
 
+#if !defined(_AIX) || defined(NCURSES_VERSION)
+/* bpo-39020 - stock AIX curses does not include ESCDELAY
+ * a third-party addtion of (gnu) ncurses might
+ */
 PyDoc_STRVAR(_curses_get_escdelay__doc__,
 "get_escdelay($module, /)\n"
 "--\n"
@@ -3161,6 +3165,7 @@ _curses_set_tabsize(PyObject *module, PyObject *arg)
 exit:
     return return_value;
 }
+#endif 
 
 PyDoc_STRVAR(_curses_intrflush__doc__,
 "intrflush($module, flag, /)\n"
@@ -4638,6 +4643,22 @@ _curses_use_default_colors(PyObject *module, PyObject *Py_UNUSED(ignored))
     #define _CURSES_HAS_KEY_METHODDEF
 #endif /* !defined(_CURSES_HAS_KEY_METHODDEF) */
 
+#ifndef _CURSES_GET_ESCDELAY_METHODDEF
+    #define _CURSES_GET_ESCDELAY_METHODDEF
+#endif /* !defined(_CURSES_GET_ESCDELAY_METHODDEF) */
+
+#ifndef _CURSES_SET_ESCDELAY_METHODDEF
+    #define _CURSES_SET_ESCDELAY_METHODDEF
+#endif /* !defined(_CURSES_SET_ESCDELAY_METHODDEF) */
+
+#ifndef _CURSES_GET_TABSIZE_METHODDEF
+    #define _CURSES_GET_TABSIZE_METHODDEF
+#endif /* !defined(_CURSES_GET_TABSIZE_METHODDEF) */
+
+#ifndef _CURSES_SET_TABSIZE_METHODDEF
+    #define _CURSES_SET_TABSIZE_METHODDEF
+#endif /* !defined(_CURSES_SET_TABSIZE_METHODDEF) */
+
 #ifndef _CURSES_IS_TERM_RESIZED_METHODDEF
     #define _CURSES_IS_TERM_RESIZED_METHODDEF
 #endif /* !defined(_CURSES_IS_TERM_RESIZED_METHODDEF) */