diff --git a/qa/qa_os.py b/qa/qa_os.py
index 143fedc53df3eb575659e9804daeabcd13767202..e6e259aadb8dc3c7408aa7d86d1cede5f29d6fe0 100644
--- a/qa/qa_os.py
+++ b/qa/qa_os.py
@@ -86,6 +86,9 @@ def _TestOsStates():
       new_cmd = cmd + ["--%s" % param, val, _TEMP_OS_NAME]
       AssertEqual(StartSSH(master["primary"],
                            utils.ShellQuoteArgs(new_cmd)).wait(), 0)
+      # check that double-running the command is OK
+      AssertEqual(StartSSH(master["primary"],
+                           utils.ShellQuoteArgs(new_cmd)).wait(), 0)
 
 
 def _SetupTempOs(node, dir, valid):