$OpenBSD$
--- Modules/mathmodule.c.orig	Mon Aug 25 15:23:28 2008
+++ Modules/mathmodule.c	Mon Aug 25 15:25:09 2008
@@ -183,7 +183,7 @@ math_1(PyObject *arg, double (*func) (double), int can
 		else
 			errno = 0;
 	}
-	else if (Py_IS_INFINITY(r)) {
+	else if (errno != EDOM && Py_IS_INFINITY(r)) {
 		if (Py_IS_FINITE(x))
 			errno = can_overflow ? ERANGE : EDOM;
 		else