diff --git a/nbd/server.c b/nbd/server.c
index 7a6f95071f8065858b1bcfcbcd6bcdbe4c109bb3..56e9b41828e8426f6e9e770f70d465817c22a844 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -2322,10 +2322,12 @@ static int coroutine_fn nbd_co_receive_request(NBDRequestData *req,
                                                Error **errp)
 {
     NBDClient *client = req->client;
+    bool extended_with_payload;
     bool check_length = false;
     bool check_rofs = false;
     bool allocate_buffer = false;
-    unsigned payload_len = 0;
+    bool payload_okay = false;
+    uint64_t payload_len = 0;
     int valid_flags = NBD_CMD_FLAG_FUA;
     int ret;
 
@@ -2338,6 +2340,13 @@ static int coroutine_fn nbd_co_receive_request(NBDRequestData *req,
 
     trace_nbd_co_receive_request_decode_type(request->cookie, request->type,
                                              nbd_cmd_lookup(request->type));
+    extended_with_payload = client->mode >= NBD_MODE_EXTENDED &&
+        request->flags & NBD_CMD_FLAG_PAYLOAD_LEN;
+    if (extended_with_payload) {
+        payload_len = request->len;
+        check_length = true;
+    }
+
     switch (request->type) {
     case NBD_CMD_DISC:
         /* Special case: we're going to disconnect without a reply,
@@ -2354,6 +2363,15 @@ static int coroutine_fn nbd_co_receive_request(NBDRequestData *req,
         break;
 
     case NBD_CMD_WRITE:
+        if (client->mode >= NBD_MODE_EXTENDED) {
+            if (!extended_with_payload) {
+                /* The client is noncompliant. Trace it, but proceed. */
+                trace_nbd_co_receive_ext_payload_compliance(request->from,
+                                                            request->len);
+            }
+            valid_flags |= NBD_CMD_FLAG_PAYLOAD_LEN;
+        }
+        payload_okay = true;
         payload_len = request->len;
         check_length = true;
         allocate_buffer = true;
@@ -2395,6 +2413,16 @@ static int coroutine_fn nbd_co_receive_request(NBDRequestData *req,
                    request->len, NBD_MAX_BUFFER_SIZE);
         return -EINVAL;
     }
+    if (payload_len && !payload_okay) {
+        /*
+         * For now, we don't support payloads on other commands; but
+         * we can keep the connection alive by ignoring the payload.
+         * We will fail the command later with NBD_EINVAL for the use
+         * of an unsupported flag (and not for access beyond bounds).
+         */
+        assert(request->type != NBD_CMD_WRITE);
+        request->len = 0;
+    }
     if (allocate_buffer) {
         /* READ, WRITE */
         req->data = blk_try_blockalign(client->exp->common.blk,
@@ -2405,10 +2433,14 @@ static int coroutine_fn nbd_co_receive_request(NBDRequestData *req,
         }
     }
     if (payload_len) {
-        /* WRITE */
-        assert(req->data);
-        ret = nbd_read(client->ioc, req->data, payload_len,
-                       "CMD_WRITE data", errp);
+        if (payload_okay) {
+            /* WRITE */
+            assert(req->data);
+            ret = nbd_read(client->ioc, req->data, payload_len,
+                           "CMD_WRITE data", errp);
+        } else {
+            ret = nbd_drop(client->ioc, payload_len, errp);
+        }
         if (ret < 0) {
             return -EIO;
         }
diff --git a/nbd/trace-events b/nbd/trace-events
index f9dccfcfb449584445bf99ec15f5e6e92b250aea..c1a3227613f0897633aefb09e510d1cf5f512f46 100644
--- a/nbd/trace-events
+++ b/nbd/trace-events
@@ -71,6 +71,7 @@ nbd_co_send_extents(uint64_t cookie, unsigned int extents, uint32_t id, uint64_t
 nbd_co_send_chunk_error(uint64_t cookie, int err, const char *errname, const char *msg) "Send structured error reply: cookie = %" PRIu64 ", error = %d (%s), msg = '%s'"
 nbd_co_receive_request_decode_type(uint64_t cookie, uint16_t type, const char *name) "Decoding type: cookie = %" PRIu64 ", type = %" PRIu16 " (%s)"
 nbd_co_receive_request_payload_received(uint64_t cookie, uint64_t len) "Payload received: cookie = %" PRIu64 ", len = %" PRIu64
+nbd_co_receive_ext_payload_compliance(uint64_t from, uint64_t len) "client sent non-compliant write without payload flag: from=0x%" PRIx64 ", len=0x%" PRIx64
 nbd_co_receive_align_compliance(const char *op, uint64_t from, uint64_t len, uint32_t align) "client sent non-compliant unaligned %s request: from=0x%" PRIx64 ", len=0x%" PRIx64 ", align=0x%" PRIx32
 nbd_trip(void) "Reading request"