Index: Include/pyport.h
===================================================================
--- Include/pyport.h	(revision 60144)
+++ Include/pyport.h	(working copy)
@@ -475,7 +475,8 @@
  *    This isn't reliable.  See Py_OVERFLOWED comments.
  *    X is evaluated more than once.
  */
-#if defined(__FreeBSD__) || defined(__OpenBSD__) || (defined(__hpux) && defined(__ia64))
+#if defined(__FreeBSD__) || defined(__OpenBSD__) || \
+	(defined(__hpux) && defined(__ia64)) || defined(__APPLE__)
 #define _Py_SET_EDOM_FOR_NAN(X) if (isnan(X)) errno = EDOM;
 #else
 #define _Py_SET_EDOM_FOR_NAN(X) ;
Index: Modules/mathmodule.c
===================================================================
--- Modules/mathmodule.c	(revision 60144)
+++ Modules/mathmodule.c	(working copy)
@@ -51,6 +51,8 @@
 math_1(PyObject *arg, double (*func) (double))
 {
 	double x = PyFloat_AsDouble(arg);
+	if (Py_IS_NAN(x))
+		return PyFloat_FromDouble(x);
 	if (x == -1.0 && PyErr_Occurred())
 		return NULL;
 	errno = 0;