diff --git a/plugins/in_prometheus_remote_write/prom_rw.c b/plugins/in_prometheus_remote_write/prom_rw.c
index 424c81e2989..a7f0d5d31b8 100644
--- a/plugins/in_prometheus_remote_write/prom_rw.c
+++ b/plugins/in_prometheus_remote_write/prom_rw.c
@@ -200,19 +200,19 @@ static struct flb_config_map config_map[] = {
     {
      FLB_CONFIG_MAP_BOOL, "http2", "true",
      0, FLB_TRUE, offsetof(struct flb_prom_remote_write, enable_http2),
-     NULL
+     "Enable HTTP/2 support"
     },
 
     {
      FLB_CONFIG_MAP_SIZE, "buffer_max_size", HTTP_BUFFER_MAX_SIZE,
      0, FLB_TRUE, offsetof(struct flb_prom_remote_write, buffer_max_size),
-     ""
+     "Maximum size of the HTTP request buffer"
     },
 
     {
      FLB_CONFIG_MAP_SIZE, "buffer_chunk_size", HTTP_BUFFER_CHUNK_SIZE,
      0, FLB_TRUE, offsetof(struct flb_prom_remote_write, buffer_chunk_size),
-     ""
+     "Size of each buffer chunk allocated for HTTP requests"
     },
 
     {