diff --git a/qa/workunits/cephtool/test.sh b/qa/workunits/cephtool/test.sh
index ecb6687d9fd75..1ad5f539b5836 100755
--- a/qa/workunits/cephtool/test.sh
+++ b/qa/workunits/cephtool/test.sh
@@ -1081,6 +1081,8 @@ function test_mon_osd()
   ceph osd set sortbitwise  # new backends cant handle nibblewise
   expect_false ceph osd set bogus
   expect_false ceph osd unset bogus
+  ceph osd set require_jewel_osds
+  expect_false ceph osd unset require_jewel_osds
 
   ceph osd set noup
   ceph osd down 0
diff --git a/src/mon/MonCommands.h b/src/mon/MonCommands.h
index b3d8e14b905ed..5d2604a34c4d5 100644
--- a/src/mon/MonCommands.h
+++ b/src/mon/MonCommands.h
@@ -628,7 +628,7 @@ COMMAND("osd erasure-code-profile ls", \
 	"list all erasure code profiles", \
 	"osd", "r", "cli,rest")
 COMMAND("osd set " \
-	"name=key,type=CephChoices,strings=full|pause|noup|nodown|noout|noin|nobackfill|norebalance|norecover|noscrub|nodeep-scrub|notieragent|sortbitwise", \
+	"name=key,type=CephChoices,strings=full|pause|noup|nodown|noout|noin|nobackfill|norebalance|norecover|noscrub|nodeep-scrub|notieragent|sortbitwise|require_jewel_osds", \
 	"set <key>", "osd", "rw", "cli,rest")
 COMMAND("osd unset " \
 	"name=key,type=CephChoices,strings=full|pause|noup|nodown|noout|noin|nobackfill|norebalance|norecover|noscrub|nodeep-scrub|notieragent|sortbitwise", \
diff --git a/src/mon/OSDMonitor.cc b/src/mon/OSDMonitor.cc
index 27c994d707934..d4408edd2eb8a 100644
--- a/src/mon/OSDMonitor.cc
+++ b/src/mon/OSDMonitor.cc
@@ -1203,13 +1203,24 @@ void OSDMonitor::encode_pending(MonitorDBStore::TransactionRef t)
     }
   }
 
+  // features for osdmap and its incremental
+  uint64_t features = mon->quorum_features;
+
   // encode full map and determine its crc
   OSDMap tmp;
   {
     tmp.deepish_copy_from(osdmap);
     tmp.apply_incremental(pending_inc);
+
+    // determine appropriate features
+    if (!tmp.test_flag(CEPH_OSDMAP_REQUIRE_JEWEL)) {
+      dout(10) << __func__ << " encoding without feature SERVER_JEWEL" << dendl;
+      features &= ~CEPH_FEATURE_SERVER_JEWEL;
+    }
+    dout(10) << __func__ << " encoding full map with " << features << dendl;
+
     bufferlist fullbl;
-    ::encode(tmp, fullbl, mon->quorum_features | CEPH_FEATURE_RESERVED);
+    ::encode(tmp, fullbl, features | CEPH_FEATURE_RESERVED);
     pending_inc.full_crc = tmp.get_crc();
 
     // include full map in the txn.  note that old monitors will
@@ -1220,7 +1231,7 @@ void OSDMonitor::encode_pending(MonitorDBStore::TransactionRef t)
 
   // encode
   assert(get_last_committed() + 1 == pending_inc.epoch);
-  ::encode(pending_inc, bl, mon->quorum_features | CEPH_FEATURE_RESERVED);
+  ::encode(pending_inc, bl, features | CEPH_FEATURE_RESERVED);
 
   dout(20) << " full_crc " << tmp.get_crc()
 	   << " inc_crc " << pending_inc.inc_crc << dendl;
@@ -3048,6 +3059,17 @@ void OSDMonitor::get_health(list<pair<health_status_t,string> >& summary,
       }
     }
 
+    // warn about upgrade flags that can be set but are not.
+    if ((osdmap.get_up_osd_features() & CEPH_FEATURE_SERVER_JEWEL) &&
+	       !osdmap.test_flag(CEPH_OSDMAP_REQUIRE_JEWEL)) {
+      string msg = "all OSDs are running jewel or later but the"
+	" 'require_jewel_osds' osdmap flag is not set";
+      summary.push_back(make_pair(HEALTH_WARN, msg));
+      if (detail) {
+	detail->push_back(make_pair(HEALTH_WARN, msg));
+      }
+    }
+
     get_pools_health(summary, detail);
   }
 }
diff --git a/src/osd/OSDMap.cc b/src/osd/OSDMap.cc
index 7961d2f96771a..45dc6d47e4efb 100644
--- a/src/osd/OSDMap.cc
+++ b/src/osd/OSDMap.cc
@@ -2385,6 +2385,8 @@ string OSDMap::get_flag_string(unsigned f)
     s += ",notieragent";
   if (f & CEPH_OSDMAP_SORTBITWISE)
     s += ",sortbitwise";
+  if (f & CEPH_OSDMAP_REQUIRE_JEWEL)
+    s += ",require_jewel_osds";
   if (s.length())
     s.erase(0, 1);
   return s;