diff --git a/src/osd/OSD.cc b/src/osd/OSD.cc
index 46a712e87dc..7fb57676275 100644
--- a/src/osd/OSD.cc
+++ b/src/osd/OSD.cc
@@ -7572,6 +7572,11 @@ void OSD::activate_map()
 
   dout(7) << "activate_map version " << osdmap->get_epoch() << dendl;
 
+  if (!osdmap->test_flag(CEPH_OSDMAP_SORTBITWISE)) {
+    derr << __func__ << " SORTBITWISE flag is not set" << dendl;
+    ceph_abort();
+  }
+
   if (osdmap->test_flag(CEPH_OSDMAP_FULL)) {
     dout(10) << " osdmap flagged full, doing onetime osdmap subscribe" << dendl;
     osdmap_subscribe(osdmap->get_epoch() + 1, false);