diff --git a/src/ngx_stream_upsync_module.c b/src/ngx_stream_upsync_module.c
index 5e71b11..59a345a 100644
--- a/src/ngx_stream_upsync_module.c
+++ b/src/ngx_stream_upsync_module.c
@@ -3669,6 +3669,7 @@ ngx_stream_client_recv(ngx_stream_conf_client *client, char **data, int size)
 
             *data = (char *) ngx_calloc(page_count * ngx_pagesize, ngx_cycle->log);
             if (*data == NULL) {
+                ngx_free(tmp_data);
                 return NGX_ERROR;
             }
             ngx_memcpy(*data, tmp_data, recv_num - tmp_recv);