diff --git a/hmp-commands.hx b/hmp-commands.hx
index e48c2ca531..6ba694d45a 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -801,8 +801,7 @@ ETEXI
         .args_type  = "value:T",
         .params     = "value",
         .help       = "set maximum tolerated downtime (in seconds) for migrations",
-        .user_print = monitor_user_noop,
-        .mhandler.cmd_new = do_migrate_set_downtime,
+        .mhandler.cmd = hmp_migrate_set_downtime,
     },
 
 STEXI
diff --git a/hmp.c b/hmp.c
index 92bb08fe6f..04e6b73810 100644
--- a/hmp.c
+++ b/hmp.c
@@ -667,3 +667,9 @@ void hmp_migrate_cancel(Monitor *mon, const QDict *qdict)
 {
     qmp_migrate_cancel(NULL);
 }
+
+void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict)
+{
+    double value = qdict_get_double(qdict, "value");
+    qmp_migrate_set_downtime(value, NULL);
+}
diff --git a/hmp.h b/hmp.h
index 2b0c1e4ab7..9182622cc0 100644
--- a/hmp.h
+++ b/hmp.h
@@ -47,5 +47,6 @@ void hmp_balloon(Monitor *mon, const QDict *qdict);
 void hmp_block_resize(Monitor *mon, const QDict *qdict);
 void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict);
 void hmp_migrate_cancel(Monitor *mon, const QDict *qdict);
+void hmp_migrate_set_downtime(Monitor *mon, const QDict *qdict);
 
 #endif
diff --git a/migration.c b/migration.c
index fa603d68e9..a5631622f0 100644
--- a/migration.c
+++ b/migration.c
@@ -490,14 +490,9 @@ int do_migrate_set_speed(Monitor *mon, const QDict *qdict, QObject **ret_data)
     return 0;
 }
 
-int do_migrate_set_downtime(Monitor *mon, const QDict *qdict,
-                            QObject **ret_data)
+void qmp_migrate_set_downtime(double value, Error **errp)
 {
-    double d;
-
-    d = qdict_get_double(qdict, "value") * 1e9;
-    d = MAX(0, MIN(UINT64_MAX, d));
-    max_downtime = (uint64_t)d;
-
-    return 0;
+    value *= 1e9;
+    value = MAX(0, MIN(UINT64_MAX, value));
+    max_downtime = (uint64_t)value;
 }
diff --git a/migration.h b/migration.h
index ff2e40b4cb..539f8f1840 100644
--- a/migration.h
+++ b/migration.h
@@ -46,9 +46,6 @@ int do_migrate_set_speed(Monitor *mon, const QDict *qdict, QObject **ret_data);
 
 uint64_t migrate_max_downtime(void);
 
-int do_migrate_set_downtime(Monitor *mon, const QDict *qdict,
-                            QObject **ret_data);
-
 void do_info_migrate_print(Monitor *mon, const QObject *data);
 
 void do_info_migrate(Monitor *mon, QObject **ret_data);
diff --git a/qapi-schema.json b/qapi-schema.json
index d638f125d9..d9b9fa10d9 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1140,3 +1140,16 @@
 # Since: 0.14.0
 ##
 { 'command': 'migrate_cancel' }
+
+##
+# @migrate_set_downtime
+#
+# Set maximum tolerated downtime for migration.
+#
+# @value: maximum downtime in seconds
+#
+# Returns: nothing on success
+#
+# Since: 0.14.0
+##
+{ 'command': 'migrate_set_downtime', 'data': {'value': 'number'} }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 5eb4b76dfc..b4cadebe96 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -518,10 +518,7 @@ EQMP
     {
         .name       = "migrate_set_downtime",
         .args_type  = "value:T",
-        .params     = "value",
-        .help       = "set maximum tolerated downtime (in seconds) for migrations",
-        .user_print = monitor_user_noop,
-        .mhandler.cmd_new = do_migrate_set_downtime,
+        .mhandler.cmd_new = qmp_marshal_input_migrate_set_downtime,
     },
 
 SQMP