diff --git a/lib/fluent/plugin/output.rb b/lib/fluent/plugin/output.rb
index 23fd29ab7e..354c6649f3 100644
--- a/lib/fluent/plugin/output.rb
+++ b/lib/fluent/plugin/output.rb
@@ -1275,7 +1275,7 @@ def update_retry_state(chunk_id, using_secondary, error = nil)
           unless @retry
             @retry = retry_state(@buffer_config.retry_randomize)
             if error
-              log.warn "failed to flush the buffer.", retry_time: @retry.steps, next_retry_seconds: @retry.next_time, chunk: chunk_id_hex, error: error
+              log.warn "failed to flush the buffer.", retry_times: @retry.steps, next_retry_time: @retry.next_time.round, chunk: chunk_id_hex, error: error
               log.warn_backtrace error.backtrace
             end
             return
@@ -1304,11 +1304,11 @@ def update_retry_state(chunk_id, using_secondary, error = nil)
             if error
               if using_secondary
                 msg = "failed to flush the buffer with secondary output."
-                log.warn msg, retry_time: @retry.steps, next_retry_seconds: @retry.next_time, chunk: chunk_id_hex, error: error
+                log.warn msg, retry_times: @retry.steps, next_retry_time: @retry.next_time.round, chunk: chunk_id_hex, error: error
                 log.warn_backtrace error.backtrace
               else
                 msg = "failed to flush the buffer."
-                log.warn msg, retry_time: @retry.steps, next_retry_seconds: @retry.next_time, chunk: chunk_id_hex, error: error
+                log.warn msg, retry_times: @retry.steps, next_retry_time: @retry.next_time.round, chunk: chunk_id_hex, error: error
                 log.warn_backtrace error.backtrace
               end
             end