diff --git a/openerp/tools/misc.py b/openerp/tools/misc.py
index 231496e7b58..9fba582ad30 100644
--- a/openerp/tools/misc.py
+++ b/openerp/tools/misc.py
@@ -122,7 +122,8 @@ def exec_pg_command(name, *args):
     prog = find_pg_tool(name)
     env = exec_pg_environ()
     with open(os.devnull) as dn:
-        rc = subprocess.call((prog,) + args, env=env, stdout=dn, stderr=subprocess.STDOUT)
+        args2 = (prog,) + args
+        rc = subprocess.call(args2, env=env, stdout=dn, stderr=subprocess.STDOUT)
         if rc:
             raise Exception('Postgres subprocess %s error %s' % (args2, rc))