diff --git a/tasks/ceph_manager.py b/tasks/ceph_manager.py
index ca8c9f693393b..962ae8d830078 100644
--- a/tasks/ceph_manager.py
+++ b/tasks/ceph_manager.py
@@ -1316,9 +1316,9 @@ def do_pg_scrub(self, pool, pgnum, stype):
         Scrub pg and wait for scrubbing to finish
         """
         init = self.get_last_scrub_stamp(pool, pgnum)
-        self.raw_cluster_cmd('pg', stype, self.get_pgid(pool, pgnum))
         while init == self.get_last_scrub_stamp(pool, pgnum):
             self.log("waiting for scrub type %s" % (stype,))
+            self.raw_cluster_cmd('pg', stype, self.get_pgid(pool, pgnum))
             time.sleep(10)
 
     def get_single_pg_stats(self, pgid):