diff --git a/src/common/config_opts.h b/src/common/config_opts.h
index e51c8847aeb..adb67b2fc02 100644
--- a/src/common/config_opts.h
+++ b/src/common/config_opts.h
@@ -320,6 +320,7 @@ OPTION(mon_cache_target_full_warn_ratio, OPT_FLOAT, .66) // position between poo
 OPTION(mon_osd_full_ratio, OPT_FLOAT, .95) // what % full makes an OSD "full"
 OPTION(mon_osd_backfillfull_ratio, OPT_FLOAT, .90) // what % full makes an OSD backfill full (backfill halted)
 OPTION(mon_osd_nearfull_ratio, OPT_FLOAT, .85) // what % full makes an OSD near full
+OPTION(mon_osd_initial_require_min_compat_client, OPT_STR, "hammer")
 OPTION(mon_allow_pool_delete, OPT_BOOL, false) // allow pool deletion
 OPTION(mon_globalid_prealloc, OPT_U32, 10000)   // how many globalids to prealloc
 OPTION(mon_osd_report_timeout, OPT_INT, 900)    // grace period before declaring unresponsive OSDs dead
diff --git a/src/mon/OSDMonitor.cc b/src/mon/OSDMonitor.cc
index a0bcb279bde..a99bd88bb94 100644
--- a/src/mon/OSDMonitor.cc
+++ b/src/mon/OSDMonitor.cc
@@ -230,6 +230,7 @@ void OSDMonitor::create_initial()
     if (newmap.backfillfull_ratio > 1.0) newmap.backfillfull_ratio /= 100;
     newmap.nearfull_ratio = g_conf->mon_osd_nearfull_ratio;
     if (newmap.nearfull_ratio > 1.0) newmap.nearfull_ratio /= 100;
+    newmap.require_min_compat_client = g_conf->mon_osd_initial_require_min_compat_client;
   }
 
   // encode into pending incremental