diff --git a/bin/build b/bin/build
index 572ee56..d550279 100755
--- a/bin/build
+++ b/bin/build
@@ -18,6 +18,7 @@ import shlex
 import shutil
 import subprocess
 import sys
+import tempfile
 
 
 
@@ -30,8 +31,8 @@ parser.add_argument('passthru', metavar='ARG', nargs='+', help='Build script arg
 config = parser.parse_args()
 
 config.worktree = os.getcwd()
-config.tmpdir = path.join(config.worktree, '.dmg')
-config.hfsimg = path.join(config.worktree, '.dmg.dmg')
+config.tmpdir = tempfile.mkdtemp()
+handle, config.hfsimg = tempfile.mkstemp(suffix='.dmg')
 config.vmac = open(path.join(path.dirname(__file__), 'vmac_path.conf')).read().rstrip('\n')