diff --git a/docs/about/deprecated.rst b/docs/about/deprecated.rst
index 1c8c8c34c4..c1613468e6 100644
--- a/docs/about/deprecated.rst
+++ b/docs/about/deprecated.rst
@@ -477,3 +477,12 @@ Use blockdev-mirror with NBD instead.
 As an intermediate step the ``inc`` functionality can be achieved by
 setting the ``block-incremental`` migration parameter to ``true``.
 But this parameter is also deprecated.
+
+``blk`` migrate command option (since 8.2)
+''''''''''''''''''''''''''''''''''''''''''
+
+Use blockdev-mirror with NBD instead.
+
+As an intermediate step the ``blk`` functionality can be achieved by
+setting the ``block`` migration capability to ``true``.  But this
+capability is also deprecated.
diff --git a/migration/migration-hmp-cmds.c b/migration/migration-hmp-cmds.c
index 83176f5bae..dfe98da355 100644
--- a/migration/migration-hmp-cmds.c
+++ b/migration/migration-hmp-cmds.c
@@ -750,6 +750,11 @@ void hmp_migrate(Monitor *mon, const QDict *qdict)
                     " use blockdev-mirror with NBD instead");
     }
 
+    if (blk) {
+        warn_report("option '-b' is deprecated;"
+                    " use blockdev-mirror with NBD instead");
+    }
+
     qmp_migrate(uri, !!blk, blk, !!inc, inc,
                 false, false, true, resume, &err);
     if (hmp_handle_error(mon, err)) {
diff --git a/migration/migration.c b/migration/migration.c
index 06a706ad90..cb2d7161b5 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -1625,6 +1625,11 @@ static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
                     " use blockdev-mirror with NBD instead");
     }
 
+    if (blk) {
+        warn_report("parameter 'blk' is deprecated;"
+                    " use blockdev-mirror with NBD instead");
+    }
+
     if (resume) {
         if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
             error_setg(errp, "Cannot resume if there is no "
diff --git a/qapi/migration.json b/qapi/migration.json
index fa7f4f2575..3765c2b662 100644
--- a/qapi/migration.json
+++ b/qapi/migration.json
@@ -1526,8 +1526,8 @@
 #
 # Features:
 #
-# @deprecated: Member @inc is deprecated.  Use blockdev-mirror with
-#     NBD instead.
+# @deprecated: Members @inc and @blk are deprecated.  Use
+#     blockdev-mirror with NBD instead.
 #
 # Returns: nothing on success
 #
@@ -1550,7 +1550,8 @@
 # <- { "return": {} }
 ##
 { 'command': 'migrate',
-  'data': {'uri': 'str', '*blk': 'bool',
+  'data': {'uri': 'str',
+           '*blk': { 'type': 'bool', 'features': [ 'deprecated' ] },
            '*inc': { 'type': 'bool', 'features': [ 'deprecated' ] },
            '*detach': 'bool', '*resume': 'bool' } }