diff --git a/test/functional/test_runner.py b/test/functional/test_runner.py
--- a/test/functional/test_runner.py
+++ b/test/functional/test_runner.py
@@ -174,7 +174,7 @@
     parser.add_argument('--quiet', '-q', action='store_true',
                         help='only print results summary and failure logs')
     parser.add_argument('--tmpdirprefix', '-t',
-                        default=tempfile.gettempdir(), help="Root directory for datadirs")
+                        default=os.path.join(build_dir, 'test', 'functional'), help="Root directory for datadirs")
     parser.add_argument('--junitoutput', '-J',
                         default=os.path.join(build_dir, 'junit_results.xml'), help="file that will store JUnit formatted test results.")