diff --git a/startup/EpicsHostArch b/startup/EpicsHostArch
index ae25ea7cd..6b102b9b9 100755
--- a/startup/EpicsHostArch
+++ b/startup/EpicsHostArch
@@ -1,11 +1,10 @@
 #!/bin/sh
 #*************************************************************************
-# Copyright (c) 2002 The University of Chicago, as Operator of Argonne
+# Copyright (c) 2011 UChicago Argonne LLC, as Operator of Argonne
 #     National Laboratory.
 # Copyright (c) 2002 The Regents of the University of California, as
 #     Operator of Los Alamos National Laboratory.
-# EPICS BASE Versions 3.13.7
-# and higher are distributed subject to a Software License Agreement found
+# EPICS BASE is distributed subject to a Software License Agreement found
 # in file LICENSE that is included with this distribution. 
 #*************************************************************************
 #
@@ -37,9 +36,9 @@ case $sysname in
     Darwin )
         os=darwin
         cpu=`uname -m`
-        case "$cpu" in
+        case $cpu in
             "Power Macintosh") cpu=ppc ;;
-            "i386") cpu=x86 ;;
+            i386 | x86_64 ) cpu=x86 ;;
         esac
         echo ${os}-${cpu}${suffix}
         ;;
diff --git a/startup/EpicsHostArch.pl b/startup/EpicsHostArch.pl
index 169f9e32e..7fb5747c8 100755
--- a/startup/EpicsHostArch.pl
+++ b/startup/EpicsHostArch.pl
@@ -1,7 +1,7 @@
 eval 'exec perl -S $0 ${1+"$@"}'  # -*- Mode: perl -*-
     if $running_under_some_shell; # EpicsHostArch.pl
 #*************************************************************************
-# Copyright (c) 2002 The University of Chicago, as Operator of Argonne
+# Copyright (c) 2011 UChicago Argonne LLC, as Operator of Argonne
 #     National Laboratory.
 # Copyright (c) 2002 The Regents of the University of California, as
 #     Operator of Los Alamos National Laboratory.
@@ -34,6 +34,7 @@ sub GetEpicsHostArch { # no args
             my($kernel, $hostname, $release, $version, $cpu) = POSIX::uname();
             if ($cpu =~ m/Power Macintosh/) { return "darwin-ppc";  }
             elsif ($cpu =~ m/i386/)         { return "darwin-x86";  }
+            elsif ($cpu =~ m/x86_64/)       { return "darwin-x86";  }
             else                            { return "unsupported"; }
     } else { return "unsupported"; }
 }