Index: unix.cpp
===================================================================
--- unix.cpp	(revision 26506)
+++ unix.cpp	(working copy)
@@ -340,11 +340,21 @@
 	int ncpu = 0;
 	size_t len = sizeof(ncpu);
 
+#ifdef OPENBSD
+	int name[2];
+	name[0] = CTL_HW;
+	name[1] = HW_NCPU;
+	if (sysctl(name, 2, &ncpu, &len, NULL, 0) < 0) {
+	        ncpu = 0;
+	}
+#else
 	if (sysctlbyname("hw.availcpu", &ncpu, &len, NULL, 0) < 0) {
 		sysctlbyname("hw.ncpu", &ncpu, &len, NULL, 0);
 	}
+#endif /* #ifdef OPENBSD */
 
 	if (ncpu > 0) count = ncpu;
+
 #elif defined(_SC_NPROCESSORS_ONLN)
 	long res = sysconf(_SC_NPROCESSORS_ONLN);
 	if (res > 0) count = res;