diff --git a/hw/core/numa.c b/hw/core/numa.c
index 4252af7100..b9e79b8c8b 100644
--- a/hw/core/numa.c
+++ b/hw/core/numa.c
@@ -118,6 +118,8 @@ static void parse_numa_node(MachineState *ms, NumaNodeOptions *node,
 
     if (node->has_mem) {
         numa_info[nodenr].node_mem = node->mem;
+        warn_report("Parameter -numa node,mem is deprecated,"
+                    " use -numa node,memdev instead");
     }
     if (node->has_memdev) {
         Object *o;
diff --git a/qemu-deprecated.texi b/qemu-deprecated.texi
index 40c017b426..ba52999f7f 100644
--- a/qemu-deprecated.texi
+++ b/qemu-deprecated.texi
@@ -88,6 +88,22 @@ The @code{-realtime mlock=on|off} argument has been replaced by the
 The ``-virtfs_synth'' argument is now deprecated. Please use ``-fsdev synth''
 and ``-device virtio-9p-...'' instead.
 
+@subsection -numa node,mem=@var{size} (since 4.1)
+
+The parameter @option{mem} of @option{-numa node} is used to assign a part of
+guest RAM to a NUMA node. But when using it, it's impossible to manage specified
+RAM chunk on the host side (like bind it to a host node, setting bind policy, ...),
+so guest end-ups with the fake NUMA configuration with suboptiomal performance.
+However since 2014 there is an alternative way to assign RAM to a NUMA node
+using parameter @option{memdev}, which does the same as @option{mem} and adds
+means to actualy manage node RAM on the host side. Use parameter @option{memdev}
+with @var{memory-backend-ram} backend as an replacement for parameter @option{mem}
+to achieve the same fake NUMA effect or a properly configured
+@var{memory-backend-file} backend to actually benefit from NUMA configuration.
+In future new machine versions will not accept the option but it will still
+work with old machine types. User can check QAPI schema to see if the legacy
+option is supported by looking at MachineInfo::numa-mem-supported property.
+
 @section QEMU Machine Protocol (QMP) commands
 
 @subsection block-dirty-bitmap-add "autoload" parameter (since 2.12.0)