diff --git a/qa/workunits/cephtool/test.sh b/qa/workunits/cephtool/test.sh
index 9140ba061dc..7fabf508fa7 100755
--- a/qa/workunits/cephtool/test.sh
+++ b/qa/workunits/cephtool/test.sh
@@ -1374,6 +1374,7 @@ function test_mon_pg()
 
   ceph osd primary-affinity osd.0 .9
   expect_false ceph osd primary-affinity osd.0 -2
+  expect_false ceph osd primary-affinity osd.9999 .5
   ceph osd primary-affinity osd.0 1
 
   ceph osd pg-temp 0.0 0 1 2
diff --git a/src/mon/OSDMonitor.cc b/src/mon/OSDMonitor.cc
index f8819255b4e..b6e0668edd6 100644
--- a/src/mon/OSDMonitor.cc
+++ b/src/mon/OSDMonitor.cc
@@ -6546,6 +6546,10 @@ bool OSDMonitor::prepare_command_impl(MonOpRequestRef op,
       wait_for_finished_proposal(op, new Monitor::C_Command(mon, op, 0, rs,
                                                 get_last_committed() + 1));
       return true;
+    } else {
+      ss << "osd." << id << " does not exist";
+      err = -ENOENT;
+      goto reply;
     }
   } else if (prefix == "osd reweight") {
     int64_t id;
@@ -6575,8 +6579,11 @@ bool OSDMonitor::prepare_command_impl(MonOpRequestRef op,
       wait_for_finished_proposal(op, new Monitor::C_Command(mon, op, 0, rs,
 						get_last_committed() + 1));
       return true;
+    } else {
+      ss << "osd." << id << " does not exist";
+      err = -ENOENT;
+      goto reply;
     }
-
   } else if (prefix == "osd lost") {
     int64_t id;
     if (!cmd_getval(g_ceph_context, cmdmap, "id", id)) {