diff --git a/tools/run_tests/port_server.py b/tools/run_tests/port_server.py
index 660928fbe79..0f81470d28f 100755
--- a/tools/run_tests/port_server.py
+++ b/tools/run_tests/port_server.py
@@ -47,7 +47,7 @@ print 'port server running on port %d' % args.port
 pool = []
 in_use = {}
 
-with open(sys.argv[0]) as f:
+with open(__file__) as f:
   _MY_VERSION = hashlib.sha1(f.read()).hexdigest()
 
 
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index c9c6498b367..2ca1f0ea697 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -548,7 +548,7 @@ def _start_port_server(port_server_port):
   if not running:
     port_log = open('portlog.txt', 'w')
     port_server = subprocess.Popen(
-        ['tools/run_tests/port_server.py', '-p', '%d' % port_server_port],
+        ['python', 'tools/run_tests/port_server.py', '-p', '%d' % port_server_port],
         stderr=subprocess.STDOUT,
         stdout=port_log)
     # ensure port server is up