diff --git a/Python/_warnings.c b/Python/_warnings.c
index fd3f629..a08219e 100644
--- a/Python/_warnings.c
+++ b/Python/_warnings.c
@@ -386,49 +386,23 @@
             show_warning(filename, lineno, text, category, sourceline);
         }
         else {
-            const char *msg = "functions overriding warnings.showwarning() "
-                                "must support the 'line' argument";
-            const char *text_char = _PyUnicode_AsString(text);
+            PyObject *res;
 
-            if (strcmp(msg, text_char) == 0) {
-                /* Prevent infinite recursion by using built-in implementation
-                   of showwarning(). */
-                show_warning(filename, lineno, text, category, sourceline);
-            }
-            else {
-                PyObject *check_fxn;
-                PyObject *defaults;
-                PyObject *res;
-
-                if (PyMethod_Check(show_fxn))
-                    check_fxn = PyMethod_Function(show_fxn);
-                else if (PyFunction_Check(show_fxn))
-                    check_fxn = show_fxn;
-                else {
-                    PyErr_SetString(PyExc_TypeError,
-                                    "warnings.showwarning() must be set to a "
-                                    "function or method");
-                    Py_DECREF(show_fxn);
-                    goto cleanup;
-                }
-
-                defaults = PyFunction_GetDefaults(check_fxn);
-                /* A proper implementation of warnings.showwarning() should
-                    have at least two default arguments. */
-                if ((defaults == NULL) || (PyTuple_Size(defaults) < 2)) {
-                    if (PyErr_WarnEx(PyExc_DeprecationWarning, msg, 1) < 0) {
-                        Py_DECREF(show_fxn);
-                        goto cleanup;
-                    }
-                }
-                res = PyObject_CallFunctionObjArgs(show_fxn, message, category,
-                                                    filename, lineno_obj,
-                                                    NULL);
+            if (!PyMethod_Check(show_fxn) && !PyFunction_Check(show_fxn)) {
+                PyErr_SetString(PyExc_TypeError,
+                                "warnings.showwarning() must be set to a "
+                                "function or method");
                 Py_DECREF(show_fxn);
-                Py_XDECREF(res);
-                if (res == NULL)
-                    goto cleanup;
+                goto cleanup;
             }
+
+            res = PyObject_CallFunctionObjArgs(show_fxn, message, category,
+                                                filename, lineno_obj,
+                                                NULL);
+            Py_DECREF(show_fxn);
+            Py_XDECREF(res);
+            if (res == NULL)
+                goto cleanup;
         }
     }
     else /* if (rc == -1) */