diff --git a/src/channel.c b/src/channel.c
index 79f4dbc..b981af4 100644
--- a/src/channel.c
+++ b/src/channel.c
@@ -2035,22 +2035,24 @@
     int
 channel_collapse(channel_T *channel, ch_part_T part, int want_nl)
 {
-    readq_T *head = &channel->ch_part[part].ch_head;
-    readq_T *node = head->rq_next;
-    readq_T *last_node;
-    readq_T *n;
-    char_u  *newbuf;
-    char_u  *p;
-    long_u len;
+    ch_mode_T	mode = channel->ch_part[part].ch_mode;
+    readq_T	*head = &channel->ch_part[part].ch_head;
+    readq_T	*node = head->rq_next;
+    readq_T	*last_node;
+    readq_T	*n;
+    char_u	*newbuf;
+    char_u	*p;
+    long_u	len;
 
     if (node == NULL || node->rq_next == NULL)
 	return FAIL;
 
     last_node = node->rq_next;
     len = node->rq_buflen + last_node->rq_buflen;
-    if (want_nl)
+    if (want_nl || mode == MODE_LSP)
 	while (last_node->rq_next != NULL
-		&& channel_first_nl(last_node) == NULL)
+		&& (mode == MODE_LSP
+		    || channel_first_nl(last_node) == NULL))
 	{
 	    last_node = last_node->rq_next;
 	    len += last_node->rq_buflen;
@@ -3006,6 +3008,12 @@
 	// Get any json message in the queue.
 	if (channel_get_json(channel, part, -1, FALSE, &listtv) == FAIL)
 	{
+	    if (ch_mode == MODE_LSP)
+		// In the "lsp" mode, the http header and the json payload may
+		// be received in multiple messages. So concatenate all the
+		// received messages.
+		(void)channel_collapse(channel, part, FALSE);
+
 	    // Parse readahead, return when there is still no message.
 	    channel_parse_json(channel, part);
 	    if (channel_get_json(channel, part, -1, FALSE, &listtv) == FAIL)
@@ -3974,6 +3982,7 @@
     sock_T	fd;
     int		timeout;
     chanpart_T	*chanpart = &channel->ch_part[part];
+    ch_mode_T	mode = channel->ch_part[part].ch_mode;
     int		retval = FAIL;
 
     ch_log(channel, "Blocking read JSON for id %d", id);
@@ -3984,6 +3993,12 @@
 
     for (;;)
     {
+	if (mode == MODE_LSP)
+	    // In the "lsp" mode, the http header and the json payload may be
+	    // received in multiple messages. So concatenate all the received
+	    // messages.
+	    (void)channel_collapse(channel, part, FALSE);
+
 	more = channel_parse_json(channel, part);
 
 	// search for message "id"