diff --git a/doc/man/8/rbd.rst b/doc/man/8/rbd.rst
index 7cecad5d31a..299e6410bc5 100644
--- a/doc/man/8/rbd.rst
+++ b/doc/man/8/rbd.rst
@@ -647,6 +647,9 @@ Per client instance `rbd device map` options:
   since 4.2 this can be used to ensure that `rbd device unmap` eventually
   times out when there is no network connection to a cluster.
 
+* lock_timeout=x - A timeout on waiting for the acquisition of exclusive lock
+  (since 4.17, default is 0 seconds, meaning no timeout).
+
 * osdkeepalive=x - OSD keepalive timeout (default is 5 seconds).
 
 * osd_idle_ttl=x - OSD idle TTL (default is 60 seconds).
diff --git a/src/tools/rbd/action/Kernel.cc b/src/tools/rbd/action/Kernel.cc
index 8d7f8af562e..3e866e976f2 100644
--- a/src/tools/rbd/action/Kernel.cc
+++ b/src/tools/rbd/action/Kernel.cc
@@ -128,6 +128,9 @@ static int parse_map_options(const std::string &options_string)
     } else if (!strcmp(this_char, "osd_request_timeout")) {
       if (put_map_option_value("osd_request_timeout", value_char, map_option_int_cb))
         return -EINVAL;
+    } else if (!strcmp(this_char, "lock_timeout")) {
+      if (put_map_option_value("lock_timeout", value_char, map_option_int_cb))
+        return -EINVAL;
     } else if (!strcmp(this_char, "osdkeepalive")) {
       if (put_map_option_value("osdkeepalive", value_char, map_option_int_cb))
         return -EINVAL;